feasibility study of demonstration sites green roofs ...demonstration sites. these first nine sites...

Final Report8th July 2013

Feasibility Study of Demonstration Sitesgreen roofs, walls and façades

Prepared by:

Growing Green Guide For Melbourne Project - Feasibility Study Of Demonstration Sites - Green Roofs, Walls and Façades

Contents

1. IntroductIon

1.1 overvIew 3

1.2 InternatIonal context 3

1.3 the SIteS 3

1.4 Methodology 4

1.5 defInItIonS 4

1.6 aSSuMptIonS - green roofS, wallS & facadeS 5

1.7 other aSSuMptIonS 6

2. aSSeSSMent crIterIa 7

2.0 aSSeSSMent crIterIa - overvIew 7

2.1 aSSeSSMent crIterIa - green roofS 7

2.2 aSSeSSMent crIterIa - green wall / facadeS 9

3. SIteS aSSeSSMentS 11

deterMInIng paraMeterS 11

3.1 rMIt cIty caMpuS, buIldIng 2 12

3.2 Melbourne town hall adMInIStratIon buIldIng 17

3.3 St KIlda lIbrary 25

3.5 222 banK Street, South Melbourne 31

3.6 north fItzroy coMMunIty hub 37

3.7 fItzroy town hall 43

3.8 poSt offIce walK, rIchMond 47

3.9 prahran MarKet car parK 50

3.10 Surrey road parK, prahran 55

project teaM

growing green guide for Melbourne project groupInner Melbourne Action Plan council representatives:

City of Melbourne

Gail Hall

Julie Francis

City of Port Philip

Lalitha Ramachandran

City of Yarra

Kevin Ayrey

City of Stonnington

Megan Jones

University of Melbourne - Green Infrastructure Research Group

Sue Murphy

John Raynor

report authorsASPECT Studios

Warwick Savvas - living architecture practitioner

FORM Structures

Barry Russell - structural engineer

Reddo

J̀ulian Cardy - building surveyor

Growing Green Guide For Melbourne Project - Feasibility Study Of Demonstration Sites - Green Roofs, Walls and Façades 3

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1. IntroduCtIon

1.1 overvIew

Figure 1. Green roofs are widespread in the Northern hemisphere, especially Germany where they are mandatory in many cities

Figure 2. Adelaide Central Living Wall - Fifth Creek Studio

Figure 3. Location of subject sites

The Growing Green Guide for Melbourne project is investigating the potential to transform Melbourne’s roofs, walls and façades into vegetated, leafy habitats.

The project is set up to create a guide for the construction of green roofs and walls to educate, inform and encourage green building development in Melbourne.

The Growing Green Guide for Melbourne is a joint initiative of the University of Melbourne and the Inner Melbourne Action Plan (IMAP) Councils - the cities of Melbourne, Yarra, Stonnington and Port Phillip. The project is funded through the Victorian Government’s Local Sustainability Accord and the four IMAP councils.

The Growing Green Guide for Melbourne Project includes recommended policy options; a guide for the design, construction and maintenance of green roofs, walls and facades; and an assessment of sites that might be suitable to be used as a demonstration sites in the IMAP Council areas.

Assessment of the feasibility of the first nine possible green roofs, wall or façade demonstration sites is the subject of this report.

1.2 InternatIonal and local context 1.3 the SIteS

In the northern hemisphere green roofs, walls and façades are well established in the building and development industry. Their significant uptake has been driven predominantly by issues related to stormwater and biodiversity, with aesthetics and social/human wellbeing benefits also taking a central role.

The drivers and benefits for green roofs, walls and façades in Melbourne are going to be specific to this city. This is due to the unique features of the city’s infrastructure. For example, unlike many North American cities we have a separated stormwater and sewer system, and we also have a legislated requirement to meet best practice guidelines for stormwater quality and quantity. Further to this, we also have a distinct climate in term of rainfall, as well as summer and winter maximum and minimum temperatures that is considerably different to the northern hemisphere.

The drivers for green roofs, walls and facades in Melbourne will be stormwater management, thermal performance, available space for human amenity, among others.

There is increasing awareness in Melbourne of green roofs, walls and façades as evidenced by media exposure of these elements and a small number of built projects. A growing number of people from the community, various levels of government, as well as the development and construction industry have now been exposed to green roofs, walls and façades in Melbourne.

The IMAP councils have conducted an opportunity assessment and have identified a number of sites in each municipality which they consider to have potential as demonstration sites. These first nine sites are the subject of the feasibility study.

The Councils considered the following when conducting the opportunities assessment:

• Planned works on particular sites which might lend themselves to incorporation of green infrastructure (redevelopments).

• Ownership of building – private and public, state or local government. Any known interest from building owners to incorporate green roofs, walls or façades.

• Likelihood of significant impact (e.g. in an urban hot spot where other works to promote cooling are likely to occur; or in a location where stormwater run-off is a particular problem).

• Planning and other regulatory requirements (e.g. planning overlays, DDA compliance).

• Strategic direction of Council and existing greening/climate adaptation/sustainability plans.

The following is a list of the first nine sites which have been selected for this study:

1. RMIT City Campus, Building 2, Melbourne

2. The Melbourne Town Hall Administration Building, Melbourne

3. St Kilda Library, St Kilda

4. 222 Bank Street, South Melbourne

5. The North Fitzroy Community Hub, Fitzroy North

6. The Fitzroy Town Hall, Fitzroy

7. Post Office Walk, Richmond

8. Prahran Market Car Park, South Yarra

9. Surrey Road Park, South Yarra


1. IntroductIon

design emphasis Benefits

thermal Improvement of building thermal performance mitigation of the urban heat island effect improvement in performance of PV arrays.

aesthetics Improved visual amenity provided by visual access by the public increase in property values.

public access Improved public amenity provided by physical access by the general public.

wSud Stormwater treatment and management.

food Social benefits associated with community gardens access to locally grown fresh food, reduction of food miles.

research / teaching Awareness raising of design professional and the public verification of benefits via monitoring and data collection.

biodiversity Provision of habitat for fauna establishment of local indigenous plant species, establishment of a basis for artificial ecosystems.

acoustic Reduction in noise impacts on building inhabitants, mitigation of external noise impacts.

air quality Improvement of local air quality, especially in proximity to mechanical air handling plant intakes improvement of global air quality by controlling broadcast of particulate contaminants to wider environment.

definitions

green roof A vegetated landscape constructed on a roof that consists of various layers, which can be installed either in modules or ‘loose laid’ over the top of the roof.

green wall Either a modular, containerised system or a fabric-based growing system erected directly on building walls and supporting largely herbaceous plants.

green façade Plants grown directly over a building wall, either climbing up or hanging down, or climbing plants utilising a specialised cabling/trellis support structure adjacent to a wall. Plants can be grown in ground or in containerised systems at height.

r value Measure of building insulation - thermal resistance

hvac Heating Ventilation and Air Conditioning

naberS The National Australian Built Environment Rating System

bca The Building Code of Australia

dda Disability Discrimination Act

1.4 Methodology 1.5 defInItIonSThe following is a description of the various benefits that the greening elements can accrue, as well as defintitions used in this study:aSSeSSMent teaM

The authors of this report include a registered Landscape Architect (and living architecture practitioner), a registered Structural Engineer, and a registered Building Surveyor.

The approach from a landscape architecture point of view extends from a thorough knowledge of water proofing and drainage, through substrate design and composition, plant selection, irrigation and stormwater capture and quality improvement, design against wind action, safety, maintenance, procurement, warrantees, and design life considerations.

The approach from a structural engineering point of view has been to assess the buildings and roof structures based on an understanding of the period in which they have been designed, and their purpose. For example Victorian buildings were not designed to accomodate large plant and equipment, and are typically of a light weight timber framed roof construction. In contrast buildings with roofs having a concrete deck constructed in the 20th Century were most likely designed to accomodate plant and equipment.

With this in mind the llikely loading capacity can be assumed based on experience. The assumptions made for each building in terms of roof load bearing capacity are provided in the Analysis section for each site.

The sites have also been assessed by a registered Building Surveyor in accordance with the following current deemed-to-satisfy provision of Building Code of Australia (BCA) 2013:

• Part C (fire rating)

• Part D (access and aggress)

• Part E (services and equipment)

• Part F (health and amenity)

• Part J (energy efficiency).

This assessment also includes the federal disabled access (DDA) legislation namely the Access to Premises - Buildings Standards 2010.

aSSeSSMent crIterIa

The criteria for assessing each building has been developed based on both a stategic as well as a technical understanding of the drivers and benefits of green roofs, walls and façades. The benefits in the context of this study are articulated Design Emphasis which has been ascribed to each site. These include consideration of climate change adaptation, mitigation of the urban heat island effect, improvement to stormwater management and biodiversity, as well as the visual and functional amenity that green roofs, walls and façades can provide for people.

The Assessment Criteria described in Section 2 have been developed with these in mind, to enable the benefits and draw backs of the various sites to be properly assessed against the objectives each Council has for the demonstration site.

Figure 4. Green roof to Chicago City Hall

Figure 5. Green facade - image courtesy of Jakob Rope systems

Figure 6. Green wall London Figure 7. Green wall 1 Bligh Street, Sydney - image Fytogreen


1. IntroductIon

type name description Assumed structural and spacial Parameters

Green roof

Extensive / semi-extensive

A vegetated roof system, comprised of a series of layers above the roof deck (upwards): waterproofing membrane, root protection layer, drainage layer, filter layer, growing substrate, irrigation, ballast, and plants.

Depth 150mm

Maximum saturated load 150kg per square metre (1.5 kPa)

Intensive A vegetated roof system with a similar buildup of layers to an extensive green roof, but with greater soil depth to enable a wider range of plants to be grown.

Depth 750mm

Maximum saturated load 750kg per square metre (7.5 kPa)

Hardscape elements (paving/decking; shade structures, site furniture etc)

Heavy elements such as trees assumed to be located over column supports

Green Wall /

Facade

Green wall (hydroponic)

Living wall system that provides full vegetative cover across an expanse of area based on non organic textile as growing support, requiring intensive fertigation.

Depth 50mm (excluding vegetation)

Maximum saturated load 50kg per square metre

Green wall (modular)

Substrate based living wall system that provides pre grown, full vegetative cover across an expanse of area based on containerised planting media vertically mounted.

Depth 300mm (excluding vegetation)

Maximum saturated load 300kg per square metre

Green façade Modular wall system that provides combination of massed vegetative cover and climbing / trailing plants supported on lattice/cable structure either planted insitu or pre grown.

Based on hybrid green façade panels consisting of:

6.0m high x 1.0m wide x 0.3m wide steel frame

Holding 3 no. rows of growing modules 250kg each (i.e. 750kg total of growing modules for each panel)

1.6 aSSuMptIonS - green roofS, wallS & facadeS

The following typlogies underpin the site assessments and findings of this study, this includes the assumptions used for implications with respect to structural loading and irrigation water demand:

Figure 8. Modular green wall panels - Fytogreen Figure 9. Green roof trials, ANZ Building Adelaide. Fifth Creek Studio

Figure 10. External hydroponic green wall - Patrick Blanc

Figure 11. Green facade - Adeliade Central Living Wall - Fifth Creek Studio

Figure 12. Detail of extensive green roof profile

Figure 13. Detail of modular green wall Figure 14. Detail of green facade


1. IntroductIon

Structural

Recommendations for structural augmentation are based on either supplementing the existing roof structure (by way of additional beams and / or purlins), or providing a new ‘floating roof’ structure to support the green roof.

Typically, most buildings will support a ‘floating roof’ over the building’s existing roof deck. Essentially, the new construction will bypass the existing roof deck itself, leaving it to support everything in it’s current state. The new floating structure will most likely comprise steelwork frame (and concrete, timber or ‘mesh’ deck) which is suppported upon existing vertical structure of the building, namely, columns or walls. These both may need to be strengthened, but experience has shown that this is often achieved and it is likely that there is spare capacity in both columns and walls, although all will need to be checked on an individual basis. Another advantage is that the weatherproofing of the exisitng roof remains intact with the exception of the local puncturing at the vertical support, which needs to be detailed appropriately.

buIldIng code of auStralIaImplementation of any green roof, wall or facade will need to comply current Building Regulations prior to construction commencing.

The following BCA references are relevant to this study:

• Public access and fire egress – Current Federal Legislation Access to Premises - Buildings Standards 2010. BCA clauses D3.1 (General building access requirements), D3.2 (Access to buildings), D3.3 (Parts of building to be accessible) & D3.5 (Accessible parking). The lift access refers specifically to clause D3.3 (f).

• Distance to fire hose reels – BCA clause E1.4 (e) for location if only 1 than within 4 m of exit if additional required for coverage than in path of travel. AS2441-2005 clauses 10.1 for location and 10.2 coverage based on 36 m hose laid on the ground with 4 m hose stream around fixtures/fittings.

• Distance to the fire hydrants – BCA clause E1.3 and AS2419.1-2005 clauses 3.2.3 & 3.2.3.2 for internal fire hydrants located in fire isolated exits or within 4m of exit with coverage based on 30m hose laid on ground with 10m hose stream around fixtures/fittings.

• Balustrade heights - BCA clause D2.16 (Balustrades or other barriers) minimum 1.0m high and where fall over to ground level greater than 4 m from floor level than no horizontal members to facilitate 150-760 mm and no gaps greater than 125mm.

• Public lighting controls and wattage – BCA clause J6.5 (Artificial lighting around the perimeter of a building).

• Stormwater – BCA clause F1.1 and AS/NZS 3500.3.

• Waterproofing – BCA clause F1.4 and AS 4564.1 & 2.

• Live loading – For public accessible building according to AS/NZS 1170.1-2002 for floor live loading 4 kPa.

• Floor area calculation per person – BCA clause D1.13 (Number of persons accommodated) from Table D1.13 (Area per person according to use).

1.7 other aSSuMptIonS

NEW CHS POST FIXED TO EXISTING "VERTICAL" STRUCTURE THEREBY BYPASSING TRANSFER OF LOAD TO EXISTING ROOF DECK

NEW ROOF DECK AND BEAM STRUCTURE

EXISTING "VERTICAL" STRUCTURE (WALL OR COLUMN)

EXISTING ROOF FRAMING

EXISTING FINISHES ANDWEATHER PROOFING

EXTENSIVE GREEN ROOF PROFILE



















Figure 15. Structural concept ‘floating roof’ - Victorian building Figure 16. Structural concept ‘floating roof’ - Modern building

Figure 17. green roof scan provide a number of benefits including building thermal performance, acoustic attentuation, and stormwater management. Image ASPECT Studios

Figure 18. green facades can improve building thermal performance, acoustic attentuation, and stormwater quality management. Image courtesy of Graeme Hopkins

buIldIng therMal perforMancegreen roof

An extensive green roof will reduce the roof surface temperatures by up to 25 degrees on hot days, and increase the thermal resistance (the R value) by up to 63%.

When operating with night time irrigation, the day time thermal resistance of the green roof is increased due to the dry substrate. Anecdotal observations suggest that night time irrigation cools the building. This could be confirmed with more research.

Fifth Creek Studio has developed an insulation design tool to predict the insulation value of intensive and extensive green roofs in a hot, dry climate. Detailed data on this can be obtained through research undertaken by Fifth Creek Studios and the University of Adelaide. This information could be incorporated into the building envelope, facade and mechanical services engineering as part of the redevelopment design.

green facades

Based on observations from Fifth Creek Studio, a green facade (similar to the Adelaide Central facade) may reduce internal heat loads on the building in summer by 35.7% or 2.4 W/m2, reducing energy demand for cooling and reduce heat loss from the building in winter by 3.6W/m2.

If planted with deciduous species a green facade will also allow thermal gain in winter, reducing winter heating energy demand “ The blanket effect of non-deciduous plants covering the façade, as in the hybrid living wall, also is of benefit, so further research needs to quantify which system is best for particular climatic conditions.

IrrIgatIon water

It is assumed that water for irrigation of all elements will be provided by on site capture and storage. The available impervious roof area for run-off collection will need to be balanced by the extent of the green roof planted area, as green roofs will reduce run-off, and consequently the water collection volume.

The size of the water storage will also need to be balanced with the available run-off produced in a typical year. This will need to be rationalised in terms of the rain fall data used to calculate volume (ie use rainfall data from an average year or a dry year?), with the short fall made up from mains water supply.

Furthermore it should be noted that intensive green roofs will produce more nutirent run-off than extensive green roofs, and this will need to be managed in terms of water quality, with the possibility of treatment required to meet Best Practice WSUD standards.


2. Assessment CrIterIA

Consideration Comments on opportunities Comments on Constraints

Green roof (green roof)

a) type of structure and load bearing capacity Existing capacity is influenced by type of structure. Heavy load bearing capacity will enable deeper substrates.

If light weight capacity, anything other than extensive green roof with no public access will require structural augmentation. Foundation type/capacity will affect load transference from roof to footing. Movement joints may also need to be considered.

b) water proofing If flexible membrane is in good condition no additional waterproofing may be required. Elements that penetrate existing water proofing will require new membrane or detailing to penetration which may impact on membrane performance and or warrantee.

c) roof slope Flat roof will not impede establishment of green roof. Slopes greater than 30 degrees will require additional support for resistance to slip.

d) Shading/sunlight availability (aspect) and exposure Aspect with semi sun will reduce irrigation water demand. Aspects with full sun will increase irrigation water demand. Aspects will full shade will limit species diversity.

e) wind considerations Sites with existing wind protection (parapets, adjacent building form) will reduce negative effects of wind action.

Sites with high exposure to wind effects will require design against wind action, especially with regard to substrate/ballast stability (prior to planting establishment) and vegetation shear.

f) Seasonal considerations Flowering time may be a factor in terms of aesthetics. Seasonal setting of seed may affect fire risk.

g) height of building Low height green roofs may be more visible from street level improving visual amenity. Tall buildings create higher wind loads.

h) access to site for cranes and other machinery Sites that have easy access for crainage will reduce construction costs. Sites with limited access for crainage will increase construction costs.

i) public accessibility potential Roofs with existing heavy load capacity will reduce cost of structural augmentation if public access is emphasised.

Roofs with existing light load capacity will increase cost of structural augmentation if public access is emphasised.

j) access for maintenance Roofs with easy access and protection from fall from height will require fewer measures for OH&S compliance.

Roofs with difficult access and protection from fall from height will require increased measures for OH&S compliance.

k) Size of usable roof area Large areas will provide greater benefits (albeit with a higher cost). Small areas will provide lesser benefits (albeit with lesser cost).

l) available water access and any collection and storage opportunities Proximity of available roof areas for collection of stormwater run-off will provide increased site irrigation water capture and re use opportunities.

Mains water will need to be supplied if there are limited options to collect rainwater. This will result in increased cost of irrigation water and may limit plant species selection options.

m) opportunities for more than one type of roof. what type of roof, intensive or extensive?

Buildings with a mixed roof loading capacity may allow an efficient mix of publicly accessible green roof areas, and extensive/working roof areas.

Buildings with a limited roof loading capacity may restrict publicly accessible green roof areas, and result in only extensive roof areas.

2.1 aSSeSSMent crIterIa - green roofS

2.0 aSSeSSMent crIterIa - overvIew

In order for the demonstration sites to successfully catalyse the widespread up take of green roofs, walls and facades they must be seen to successfully provide the benefits they offer. They must also serve as useful working examples that can provide the necessary data to confirm that these benefits can be achieved in a cost effective manner.

Each site has been assessed based on a number of specific criteria with the design emphasis being used to inform the comments made. These comments are then synthesised to provide the findings.

The assessment criteria of the greening elements are defined for each building in this section.

The detailed Site Assessments and Findings are then provided in Section 3.


2. Assessment CriteriA


Green roof (green roof)

n) access to utilities (water, electricity) Sites with advantageous hydraulic and electrical services provision will facilitate irrigation water reticulation.

Hydraulic and electrical services will need to be provided for irrigation and public utility such as lighting and food and beverage service if the roof is to include a cafe.

o) existing use/s of building (e.g. commercial, residential) Sites with difficult body corporate arrangements may make implementation of green roofs difficult. Sites without potential to capitalise of retail advantages of green roofs may impede on financial incentives for developers to fund projects.

Sites with no body corporate restrictions will facilitate implementation of green roofs Sites with potential to capitalise on retail advantages of green roofs may provide financial incentives for developers to fund projects.

p) existing energy use of building (to determine whether heating and cooling requirements will be reduced)

Buildings with poor insulation will benefit from the increased R value of the green roof (especially during summer with night time irrigation).

Buildings with higher levels of existing insulation will benefit less.

q) consideration of integration of green roof with pv arrays Buildings which could accommodate PV arrays will benefit from the lowering of roof top temperatures which will increase performance of these systems.

Buildings in shade may not be viable for PV power generation. Those with limited roof space will constrain the extent of the green roof.

r) likelihood that a demonstration site would face hurdles in terms of planning and building permit requirements/restrictions, heritage issues

Would the green roof compliment planning and heritage overlays, heritage and conservation management studies, Heritage listings and significance?

Would the green roof compromise planning and heritage overlays, heritage and conservation management studies, heritage listings and significance?

s) likelihood that a demonstration site would face hurdles in terms of accessibility for disabled persons

The public accessibility to the green roof will meet DDA requirements. The public accessibility to the green roof will not meet DDA requirements.

t) building code of australia Consideration of issues associated with the BCA including public access and fire egress / distance to fire hose reels and hydrants, balustrade heights public lighting controls and wattage

u) any existing noise concerns (e.g. plant equipment) Will the green roof suppress (mitigate) internal noise issues? (contribute to acoustic insulation to buffer external noise impacts on building inhabitants).

Will the green roof mitigate external noise issues? (contribute to acoustic insulation to reduce internal noise impacts on neighboring communities).

n/a

v) Safety considerations (parapet height/railing requirements) Whether the site provides existing parapet to not warrant additional fall from height protection.

Whether the site does not afford necessary parapet and will require additional fall from height protection.

w) fire risk Fire risk dependent on final planting design. Contribution of substrate to fire risk control.

Fire risk dependent on final planting design. Flammability of species will require consideration and confirmation from the fire authority that there is no increased fire risk.

x) Stormwater discharge point of building Sufficient down pipes and roof drainage to discharge required run-off to meet building code requirements.

Insufficient down pipes and roof drainage to discharge required run-off to meet building code requirements.

2.1 aSSeSSMent crIterIa - green roofS




Green wall / facade (green wall & façade)

a) type of structure and load bearing capacity Existing capacity is influenced by type of structure. Heavy load bearing capacity will enable more continuous planter extent, and more sophisticated support structure for green wall / facade.

Light weight capacity will restrict potential green wall / facade system to textile substrate, or limited planter extent.

b) drainage considerations Recirculation of irrigation run-off into planters or catchment below. If public access below, run-off will need to be controlled.

c) Shading / sunlight availability (aspect) and exposure Aspect with semi sun will reduce irrigation water demand. Aspects with full sun will increase irrigation water demand. Aspects will full shade will limit species diversity.

d) wind considerations Sites with existing wind protection will reduce negative effects of wind action. Sites with high exposure to wind effects will require design against wind action, especially with regard to vegetation shear.

e) Seasonal considerations Deciduous species may provide increased thermal gain (sunlight) in winter versus increased shading in summer ( façades)

Deciduous species generate increased leaf litter, and reduced biodiversity value for native fauna

f) height of building Low walls will provide increase visual and physical accessibility. Tall buildings create higher wind loads. Access for maintenance will be difficult on taller buildings

g) access to site for cranes and other machinery Sites that have easy access for crainage will reduce construction costs. Access for maintenance will be required (façade mounted, or ground based (scissor lift).

Sites with limited access for crainage will increase construction costs. Site with no ground based access will require specialised maintenance access.

h) access for maintenance Green wall / facades with easy access and protection from fall from height will require fewer measures for OH&S compliance.

Green wall / facades with difficult access and protection from fall from height will require increased measures for OH&S compliance.

i) Size of useable wall or façade area Large areas will provide greater benefits (albeit with a higher cost). Small areas will provide lesser benefits (albeit with lesser cost).

j) available water access and any collection and storage opportunities Proximity of available roof areas for collection of stormwater run-off will provide increased site irrigation water capture and re use opportunities.

Limitation of available roof areas for collection of stormwater run-off will provide limited site irrigation water capture and re use opportunities.

k) available space for plants to be grown from ground level upwards Establishment of on ground planting will facilitate ease of vegetative cover. If no on ground area for establishment of plants then building mounted vegetation will be necessary.

l) opportunities for more than one type of wall or façade. what type of green wall / facade (continuous / modular?)

Buildings with a range of mounting opportunities may allow an efficient mix of green wall / facade types.

Buildings with a limited range of mounting opportunities may constrain mix of green wall / facade types.

m) access to utilities (water, electricity) Sites with advantageous hydraulic and electrical services provision will facilitate irrigation water reticulation.

Sites with disadvantageous hydraulic and electrical service provisions will impede irrigation water reticulation.

n) existing use/s of building e.g. commercial, residential Sites with difficult body corporate arrangements may make implementation of green wall / facades difficult.

Sites with no body corporate restriction will facilitate implementation of green wall / facades.

2.2 aSSeSSMent crIterIa - green wall / facadeS




Green wall / facade (green wall & façade)

o) existing energy use of building (to determine whether heating and cooling requirements will be reduced)

Buildings with poor insulation will benefit from the increased R value of the vertical garden (especially during summer with night time irrigation). Percentage of glazed/translucent façade area will influence building thermal differently in summer and winter (ie important to shade glazed areas in summer, yet allow sun penetration in winter).

Buildings with higher levels of existing insulation will benefit less.

p) likelihood that a demonstration site would face hurdles in terms of planning and building permit requirements/restrictions, heritage issues

Would the green wall / facade compliment heritage values? Would the green wall / facade compromise heritage values?

q) any existing noise concerns (e.g. plant equipment) Will the green wall / facade suppress (mitigate) internal noise issues? (contribute to acoustic insulation to buffer external noise impacts on building inhabitants).

Will the green wall / facade mitigate external noise issues? (contribute to acoustic insulation to reduce internal noise impacts on neighboring communities).

n/a

r) Safety considerations The site affords beneficial parapet to not warrant additional fall from height protection. The site does not afford necessary parapet and will require additional fall from height protection.

s) fire risk Fire risk dependent on final planting design Fire risk dependent on final planting design.

t) Stormwater discharge point of building Sufficient down pipes and roof drainage to discharge required run-off to meet building code requirements. Recirculation of irrigation run-off into planters or catchment below (Refer Item 2.2.2 Drainage considerations).

Insufficient down pipes and roof drainage to discharge required run-off to meet building code requirements. Consideration of potential nutrient loading to receiving stormwater system may require Melbourne Water approval if WSUD best practice is required.

2.2 aSSeSSMent crIterIa - green wall / facadeS


3. sItes Assessments

deterMInIng paraMeterS

The findings of this feasibility study are based on the issues arising out of the Assessment Criteria. The following parameters for the green roof, wall or façade for each site will be used to illustrate the findings:

green roofS1. Structural capacity

2. Water proofing

3. Drainage

4. On-site capture and storage of stormwater for irrigation re use

5. Wind effects

6. Building thermal performance

7. Noise

8. Potential for increased performance from photo voltaic arrays on the roof

9. Potential for increased performance of HVAC services on the roof

10. Visual amenity

11. Urban food production

12. Biodiversity and urban habitat

13. Building code compliance

14. Access for construction

15. Access for maintenance

16. Access for the public

17. Heritage

green wall / facadeS1. Structural capacity

2. On-site capture and storage of stormwater for irrigation re use

3. Wind effects

4. Building thermal performance

5. Noise

6. Visual amenity

7. Urban food production

8. Biodiversity and urban habitat

9. Building code compliance

10. Access for construction

11. Access for maintenance

12. Heritage

coMMentS

The comments that are made based on these determinaing parameters form the key findings for this feasibility study. Note that these comments are what the authors consider practical and best value propositions, and are not exhaustive in their scope of scale. It will be the task of any Concept Design phase of a potential project to flesh out the detail of the various gardens proposed.

Notwithstanding this, where appropriate, three dimensional representations of the potential garden treatment has been provided to illustrate these possibilities. These representations are for discussions purposes only and do not constitue design proposals. It is the authors intent that they will provide a point of reference and communicate a possibility for each site that may engender increased enthusiasm from the relevant stakeholders.


3. SiteS ASSeSSmentS

design emphasis

thermal

wSud

research / teaching

public access

acoustic

air quality

3.1 rMIt cIty caMpuS, buIldIng 2

3.1.1 analySIS

overvIew

Built in 1916, this building is a double brick construction of an art deco style. It accommodates the departments of the School of Art, College of Design and Social Context.

The roof space is easily accessible and currently provides some informal amenity to the building users. The RMIT has undertaken an energy and water review of all building assets under the Department of Treasury and Finance’s ‘Greener Government Building’ program, which has included Building 2.

The building façades have 25% glazed area and face to the south and east. As such the opportunity to influence thermal performance with a green façade is low and only a green roof has been considered in this study. It should be noted that a green wall could be considered as a screening device to the HVAC plant and equipment to mitigate visual and noise impacts, but this has not been assessed in detail.

garden for conSIderatIon

green roofAt the time of the site assessment, the RMIT Landscape Architecture Program has been undertaking a green roof design studio and the momentum from this will assist in supporting the green roof proposal.

The green roof could provide a number of benefits which include; user amenity (opportunities for people to occupy the space with seating and shade); education and research benefits in terms of built environment students and green infrastructure. Other potential benefits include improved thermal performance of the building as well as potential acoustic improvements and improvements in air quality with respect to air handling / HVAC plant and equipment.

Consideration Comments

Green roof

a) type of structure and load bearing capacity

The building structure comprised of a combination of load bearing masonry walls and frame, most likely steelwork. The roof structure appears to be concrete slab construction with a potential live load capacity of 3.0kPa.

This assessment has been based upon both the feeling underfoot of the ‘solid’ concrete slab and by visual inspection. Given the building’s age and use, it is highly likely that the space has been designed for roof mounted plant and equipment. Based on the experience of the structural engineer it is most likely that the slab would be confirmed by calculation to support the loads above.

b) water proofing The existing water proofing is comprised of the concrete roof slab with an applied bituminous membrane. This has been patched in a number of areas, and potentially replaced over the years. The majority of membrane observed appears to be less than 10 years old.

c) roof slope The roof is of a very flat pitch (approximately 1:100 or flatter).

This is conducive to a green roof, and will make access and maintenance simple.

d) Shading / sunlight availability (aspect) and exposure

The southern section of the roof has a south and eastern orientation, however it is still subject to near full sun exposure.

The northern section of the roof is more protected and partially shaded.

e) wind considerations The northern section of the roof is somewhat protected from wind by the existing roof top structures, and wind effects should not be severe.

The southern section of the roof has a balustrade of approximately 1.6m height which will afford good wind protection even with the more exposed orientation of the roof.

f) Size of useable roof area The area available for a green roof is considerable (approximately 165 square meters). This could be a combination of green roof (planted area) and hardscape (paving, decking, site furniture, shade elements etc.) subject to loading constraints.

Figure 19. Location plan

Figure 20. View to South

Figure 21. View to East Figure 22. Roof Space with level below. Walls shown greyed out Figure 23. Repairs to water proofing maintence




3.1.1 analySIS

Figure 24. The flatness of the roof makes it conducive to a green roof.


Green roof

g) height of building The building is a five story structure, with ground to roof height approximately 17m from street level. Refer Item e) for wind considerations.

h) access for construction Access for construction from Bowen Lane is possible. Access for construction from Latrobe Street would require closing of one lane of vehicle traffic as well as the cycle lane, which may be acceptable.

i) access for maintenance Access for maintenance is easily provided via the existing lifts.

j) potential for public access DDA compliant access can be provided via the existing lifts, which are suitable for public access. The load bearing capacity of the roof can accommodate this, however this is at present in the absence of any additional live loads (such as a green roof)

If the existing capacity is insufficient to carry the imposed loads of an extensive green roof and a limited number of people, then it will need to be increased. A 'floating' green roof will need to be provided such that the dead and live loads can be transferred to the building structure without imposing additional load on the existing roof slab.

The existing parapet provides adequate protection from fall from height.

Consideration will need to be given to accommodation / mitigation of the impacts of alcohol consumption in terms of OH&S implications of people and projectiles (bottles) falling from balustrades. Appropriate design of the capping to the parapet can mitigate these risks.

k) opportunities for site capture and storage of water for irrigation

There is existing storages to the east of Bowen Street, however this water is allocated for other irrigation uses, and it would be difficult to bring a supply line across Bowen Lane due to the presence of existing underground services.

The existing roof drainage, gutters and down pipes may provide efficient collection points to a water storage tank.


Green roof

l) opportunities for more than one type of roof. what type of roof, intensive or extensive?

Pending confirmation of load bearing capacity, and feasibility of providing public access, it is possible that the green roof could combine hardscape areas, site furniture and shading, along with the planted green roof areas of a variety of depths.

m) factors associated with existing hvac services and other roof mounted equipment

There is a considerable amount of HVAC plant on the roof which includes a steel enclosure that contains 2 no. boilers and heating hot water pumps and an open enclosure that contains industrial sized dust extractor fans, and split unit reverse cycle air conditioners that occupy a significant amount of space.

This is currently arranged in a relatively unconsolidated manner. The newer refrigerated cooling system is housed in a steel enclosure. The older plant is out in the open and would require screening if the space was to be developed as a green roof.

The building currently uses 255kL of water for toilet flushing, which is over 50% of all water used. HVAC related electrical energy use is 33% for ventilation and air handling and a further 26% for pumps.

The dust extraction fans have tall ventilation stacks, however particulate air pollution may be an issue for the green roof.

The roof is well serviced by potable water, electrical connections, and the provision of reticulated recycled water for irrigation would not be difficult (provided a storage tank is available).

n) existing use/s of building e.g. commercial, residential

The existing use of the building within an education precinct makes it conducive to being a publicly accessible green roof.

There is an opportunity to include the green roof as an educational asset, outdoor class room, green roof research subject, green roof maintenance training etc.

o) opportunity for improvement of building thermal performance

The existing concrete roof would provide little thermal resistance and would not meet current BCA or NABERS standards.

p) consideration of integration of green roof with pv arrays

There is great potential to include PV arrays on the roof, especially co located with the planted green roof. The improved efficiency of output on hot days could be included in the cost/benefit assessment and sizing of the PV system.

Figure 25. There are a number of potential locations on ground water storage tanks.




Green roof

q) factors associated with town planning, building permits, bca compliance and heritage issues

The building is currently within a heritage overlay in the Melbourne Planning Scheme although it is not listed in the Victorian Heritage Register (336-338 La Trobe Street).

There a number of existing integrated sub buildings (potentially of heritage significance) and associated elements on the northern part of the roof which should be considered in relation to heritage.

The building directly to the north is considered to have a high level of heritage value and any work which affected this would need to be considered by Council.

Given that the existing parapet is of a significant height the visual impact from street level of any green roof elements would be negligible.

r) factors associated with noise The existing HVAC plant generates a significant amount of noise. Consideration will need to be given to the impacts of this on the amenity of users if the roof was to be developed as a green roof.

A green roof will contribute to noise mitigation of the occupiable spaces below, as it can provide acoustic attenuation. An acoustic consultant could be engaged to provide a noise attenuation value for a green roof based on existing comparable roofs (e.g. the Desalination Project Green Roof which was reviewed and assessed by Marshall Day acoustic consultants).

s) Safety considerations (parapet height/railing requirements)

The existing parapet provides adequate protection from fall from height. Due to the potential presence of asbestos there would need to be a Hazmat overlay for this space and the investigation will need to be undertaken and safe removal will need to be arranged.

t) fire risk Provided plant species are not highly flammable, and access is adequate there should not be any issues from a fire risk point of view. MFB will need to approve the final design in terms of flammability and access to fight a fire.


3.1.1 analySIS

Figure 26. The roof currently houses a significant amount of HVAC plants, which poses nose and visual intrusions

Figure 27. Existing plant and equipment



3.1 rMIt cIty caMpuS, buIldIng

3.1.2 fIndIngS

SuMMary

The opportunity for the provision of a green roof to this building is considered great especially in the context of the university’s built environment design faculty’s interest in green infrastructure in general and green roofs in particular.

The RMIT Landscape Architecture Program could be a driver of the scope and performance requirements for the roof, as it would afford both design exploration and scientific monitoring opportuniities.

Furthermore given the ESD review under the ‘Greener Government Building’ program, the opportunity exists for the roof to play a direct role in the water and energy conservation agenda for the campus. The water storage that will be required to irrigate the green roof so that the plantings can tollerate the summer period, can be used for toilet flushing during winter which will significantly reduce the building’s water consumption and contribute to the sustainability of the campus.

The creation of an outdoor learning area on the roof will provide valuable space in what is a highly restricted and congested campus setting. The green roof will make this space signifiantly more aesthetically pleasing and improve human comfort levels especially on warm and hot days.

The simple existance of a green roof on Building 2 will provide invaluable benefits in terms of raising awarenss of the issues of urban sustainability and the possibilities our cities can realise through design innovation and integration of vegetation.

determing Parameter Comments

Green roof

a) Structural capacity The existing roof structure will likely be able to carry an extensive green roof, plus a limited number of people without structural augmentation. The amount of structural augmentation to the existing roof structure to accommodate a green roof will be dependant on whether the roof is accessible to the public or not.

If it is to be accessible to the public then a live load of 3.0 kPa will be required for people, and an additional 1.5 kPa for the green roof self / weight (assuming it will be an extensive green roof). This is a total of 4.5 kPa which exceeds the current likely capacity. There are two obvious solutions:

1. to bypass the existing roof structure by constructing a new (timber and steelwork frame) deck over and directly loading the columns and walls under, or

2. load directly upon the roof deck structure and strengthen accordingly by way of additional timber frame strengthening or additional steelwork beams.

If the roof is not to be accessible to the public then an extensive green roof could be accomodated without structural augmentation. If this was the case a 1.5 kPa live load allowance could be achieved (for people), and a 1.5 kPa live load for the green roof. This would allow limited numbers of people (up to 100 people over a 50 square metre area based on 75kg per person), to access the roof at a time. This would facilitate class sized groups accessing the roof for education and research purposes, but would preclude public access or groups larger than this.

b) water proofing The existing water proof membranes are currently exposed and as a result their life cycle is diminished. The provision of a green roof as a protective covering to these will extend the design life of the membrane and reduce maintenance and replacement costs.

c) drainage The existing perimeter drainage system is suitable for integration with the green roof. The design must ensure free drainage to the existing down pipe collection points.

Figure 28. Existing building from the north west

Figure 29. Existing building from the south east

Figure 30. Refer to Item c) roof drainage points Figure 31. Refer to Item d) potential storgae tank location




Green roof

d) on-site capture and storage of stormwater for irrigation re use

There is an opportunity for site collected stormwater for irrigation reuse. This would need to integrate with the campus Intelligent Water Management System and Water Conservation Plan.

The existing down pipes to Building 2 are concealed and it may be difficult to capture roof stormwater run-off via these. It may be more practical and cost effective to capture roof run-off from the adjacent building and collect water in surface mounted water tanks in the courtyard to the north-west of Building 2, either against the building in the existing garden bed, or under the external stairs.

e) wind effects The presence of the existing 1.6m high parapet will afford the neccessary wind protection to ensure that wind impacts are reduced.

Consideration should also be given to selection of substrate composition, and plant species in terms of tollerance of wind effects.

f) building thermal performance There is potential for the green roof to provide thermal performance improvements in terms of an increase in R value of roof insulation. This could reduce the energy required to cool the building.

Summer heat loads on the building could be reduced with the inclusion of an extensive green roof. The order of reduction in roof temperature is 25 degrees Celcius on hot days. This, combined with night time irrigation could significantly reduce internal building temperatures.

The thermal resistance of the roof will also be improved with the inclusion of a green roof, however there is insufficient research to ascribe a particular R value. Studies have shown however that this could be in the order of a 60% improvement.

g) noise The presence of the existing HVAC plant on the roof poses issues with regard to noise levels for occupants of the roof space. There may be a requirement to consider noise attenuation (screening) to this equipment.

The presence of an extensive green roof will provide attenuation of noise from this equipment to the internal occupants of the building.

h) potential for increased performance from photo voltaic arrays on the roof

If photo voltaic panels were to be provided on the roof for generation of electrical energy for the building, their performance on hot days could be significantly improved due to the cooling effect of a green roof (up to 25 degrees Celcius).


Green roof

i) potential for increased performance of hvac services on the roof

Future works under the Greener Government Building Program will require a low risk investment orientated approach to procuring energy efficiencies through building retrofits known as ‘energy performance contracting’. Accordingly the opportunity exists to integrate and future upgrade of the buildings heating and cooling system with the thermal performance benefits of the green roof (subject to confirmation of R value, and heat load reduction).

The air quality improvement potential of the green roof should also be considered from air intake plant in terms of removal of particulates, and lowering of roof temperatures on hot days.

j) visual amenity Inclusion of a green roof will be visible from a number of multi story buildings (both from within and outside of the RMIT city campus).

k) urban food production Depending the the research agenda for the green roof, food production for educational and scientific purposes is possible. This may require marginally deeper substrate depths (greater than 200mm).

l) biodiversity and urban habitat There is potential for the green roof to be a research subject on the factors associated with ecological values (e.g. habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.

m) building code compliance The roof space is compliant with respect to the BCA as the existing lift provides disable lift access with exit travel distance to nearest single exit of less than 20m.

Compliant exit door signage and door hardware will be required.

Fire hose hydrant (30 m hose with 10 m hose stream) and hose reel (36 m hose) coverage will be required.

The eventual design population would be determined by number of exits (exit width), live load of floor. The requirement of 2 square metres per person.

Any exterior lighting will require compliant energy efficiency ratings in terms of control and wattage.

n) access for construction Construction of a green roof on this site will be acheivable with crane access from Bowen Lane, and using the existing lift.


3.1.2 fIndIngS



3.2 Melbourne town hall adMInIStratIon buIldIng 3.2.1 analySIS

overvIew

The building constructed in 1908, is comprised of solid masonry walls with a combination of timber and concrete internal floors. The roof is of lightweight construction with timber roof framing and a bitumen tanked roof. There have been a number of modifications to the building over the years with the removal of a number of internal walls at the lower levels.

GaRDenS FoR ConSiDeRation

green roofThe City of Melbourne has redevelopment plans for the building which includes consideration for the provision of a publicly accessible roof top cafe and green roof. The refurbishment will show case sustainable design principles.

The green roof could be part of a publicly accessible space, or a non accessible ‘working’ green roof (ie one that provides thermal, WSUD, and biodiversity values).

green wall / facadeThe green wall proposition that is considered in this study is that of a green wall. Consideration could also be given to green wall / facades on the roof top to provide visual and acoustic screening to the roof mounted HVAC plant, however this has not been assessed in detail.


Green roof


The building structure comprises of a combination of load bearing masonry walls and steelwork framing with a combination of concrete and timber floor constructions. The roof is a timber framed construction with appropriate weatherproofing above. It is assumed to be designed for maintenance purposes only, having a load bearing capacity of 1.5kPa.

This has been based upon experience of Victorian buildings and exploratory works which confirmed that the roof structure is timber framed (lightweight construction).

b) water proofing The existing water proofing is comprised of an applied bituminous membrane. This has been replaced a number of times over the years and the majority of membrane observed appears to be less than 5 years old. The costs associated with replacement of this membrane could be significantly reduced if the green roof proceeds as it will no longer be exposed.

c) roof slope The roof is of a relatively flat pitch (approximately:80 or flatter). This is conducive to a green roof, and will make access and maintenance simple.


The roof has a northern and western orientation which provides near full sun exposure. Early morning sun will be shaded by the adjacent taller Victoria Hotel building to the east. Late afternoon sun will be shaded by the taller buildings directly opposite to the west of Swanston Street.

e) wind considerations Wind exposure will be influenced by the urban canyon effect down Swanston Street, which is a north/south flow. The absence of a solid parapet to the west, north, and southern roof edge means that wind effects will need to be mitigated with a perimeter ballast zone, and potentially other measures.

f) Size of usable roof area The area available for a green roof is considerable (approximately 570 square metres). Some of this will need to be a ballast zone for the mitigation of wind effects. The remainder could be a combination of green roof (planted area) and hardscape (paving, decking, site furniture, shade elements etc), subject to loading constraints.

design emphasis

a) thermal

b) public access

c) aesthetic

d) wSud

e) biodiversity

f) research / teaching


Figure 34. Isometric

Figure 35. Light weight roof framing with services in crawl space Figure 36. The existing water proof membrane has required on going maintenance

Figure 32. Adjacent Victoria Hotel building will shade early morning sun but affords some wind protection



3.2 Melbourne town hall adMInIStratIon buIldIng

3.2.1 analySIS

Figure 37. The eastern side affords good views to the north west, and provides and aspect for full suna dn wind exposure

Figure 38. The existing heritage balustrade may be of significance


Green roof

g) height of building The building is a five story structure, with ground to roof height approximately 21m from street level. Refer Item 3.2.5 for wind considerations.

h) access for construction Access for construction from Swanston Street would require closing of one traffic lane on Swanston Street, which may be practically achievable, but may incur a significant cost .

Access from Little Collins Street may be possible but would require closing the entire street. The distance from Little Collins Street to the roof being 20m is within the reach of a large mobile crane.

i) access for maintenance If public access is not practical and a green roof is installed without a compliant balustrade; due to the considerable proportion of the roof perimeter that has no effective fall restraint a system of static line anchors will need to be provided.

j) potential for public access The primary determinant for public access is the load bearing capacity of the roof. If the existing capacity is insufficient then it will need to be either increased, or a 'floating' green roof will need to be provided such that the dead and live loads can be transferred to the building structure without imposing additional load on the existing roof structure.

The provision of DDA compliant access to the roof will depend on the feasibility of extending the existing lift over run up to roof level. If this is not practical then public access will be restricted to stairs. It may be feasible and DDA compliant to provide a stair lift facility if the former lift extension option is not feasible.

If public access is to be provided then a considerable extent of perimeter barrier or balustrades will be required. The existing old wrought iron balustrade is not suitable. Provision of a new balustrade would require consideration from a heritage point of view.


Green roof


The existing roof drainage, gutters and down pipes may provide efficient collection points to a water storage tank. There is an opportunity for site collected stormwater for irrigation re use to be stored in the existing ground floor storage vaults below the skylight area to the east of the Front Desk Waiting Area. Consideration for a green wall could be given to the area above this on the 1st Floor. This would replace (or be integrated with the existing sculptural piece. Refer wall assessment.

Consideration will need to be given for recovery of the run-off from the green roof for irrigation reuse. Implications of this with regard to meeting Melbourne Water’s Best Practice Guidelines for WSUD will need to be assessed in terms of nutrient loading of stormwater run-off. The implications of the performance of the planting with respect to repeated cycling of recovered run-off for irrigation will also need to be assessed.


With structural augmentation it is possible that an extensive green roof could combine hardscape areas, site furniture, and shading, along with the planted green roof areas.

Major structural augmentation would facilitate an intensive green roof, albeit at increased cost.


The report produced by Irwinconsult - City of Melbourne Administration Building Redevelopment ESD Opportunities Report 18 July 2012 Revision 1 notes the 'lack of synergy with existing HVAC systems, which have been selected and installed in a piecemeal fashion through the life of the building'.

It may be possible to consolidate the existing HVAC system with the recently installed refrigerated cooling system on the adjoining Melbourne Town Hall building. It would free up space for the green roof on the Administration Building and remove a considerable amount of noisy plant and equipment which will improve the amenity of the green roof.

There is an existing stair case pressurisation exhaust discharge on the roof, which may require reconfiguration if public access were to be provided. This may also require a review of the proposal in terms of fire engineering.

Figure 39. Existing lift overun Figure 40. Internal perimeter gutters drain the majority of roof area

Figure 41. Access cover to roof crawl space




Green roof


The existing roof is comprised of minimal insulation (if any). It would not meet current BCA Part J1 which requires an R value of 3.

The existing use of the building as a public asset and Council office makes it conducive to being a publicly accessible green roof. There is an opportunity to increase the amount of accessible green open space in the city by providing this green roof.


The existing roof has no effective insulation and would provide little thermal resistance. As such it would not meet current BCA or NABERS standards.

p) consider of integration of green roof with pv arrays

There is great potential to include PV arrays on the roof, especially co located with the planted green roof. The improved efficiency of output on hot days can be included in the cost/benefit assessment and sizing of the PV system.

Figure 43. Reticulation across roof of HVAC pipe work Figure 44. Stair case pressurisation exhaust discharge Figure 45. Existing plant and equipment clutters the roof areaFigure 42. Ground floor storage vaults below the skylight area to the east of the Front Desk Waiting Area could be a location for a water storage tank


3.2.1 analySIS


Green roof


The building has significant heritage values being a ‘Federation style Town hall exemplar building’ (Victorian Heritage Register H0001).

In 1888 the Melbourne Council bought the then Police Court building securing a site for future offices. In 1908 a building was erected on this site to accommodate the administrative staff, including the office of the Town Clerk, and also incorporated committee rooms and a new council chamber. The exterior was designed by J. J. and E. J. Clark, emulating much of the detail of the adjacent Town Hall building, and the interior was completed by Grainger, Little and Barlow. The council chamber has been the meeting place of the City Council since 1910 and its design displays a post-Federation pride in Australian materials and has highly significant heritage values.

There are currently two perimeter wrought iron barriers to the Swanston Street, and Little Collins Street sides of the roof. The inner seems to be a non compliant balustrade, while the outer is a decorative feature (max. 600mm high) most likely original.

It is likely that any new balustrading would need to be set back from the edge of the roof so as not to be visible form street level. This would be advisable also from an OH&S point of view given potential for public access.

The existing slate turret roofs at the north and southern corners contribute to the heritage character of the roofscape.

Due to the high heritage significance of the Administration Building itself and specifically the Council chamber, any potential impact from elements associated with the green roof (eg water tanks) is not advised.




Green roof

r) factors associated with noise

Acoustic considerations are identified in the report produced by Irwinconsult - City of Melbourne Administration Building Redevelopment ESD Opportunities Report 18 July 2012 Revision 1 - User Health.

A green roof will contribute to noise mitigation as an acoustic treatment. An acoustic consultant could be engaged to provide a noise attenuation value for a green roof based on existing comparable roofs (eg the Victorian Desalination Project Green Roof which was reviewed and assessed by Marshall Day acoustic consultants).


There are existing fixed anchor points for maintenance access to existing plant and equipment including the HVAC systems.

t) fire risk MFB will need to approve the final design in terms of flammability and access to fight a fire. Provided plant species are not highly flammable, and access is adequate there should not be any issues from a fire risk point of view.

u) Stormwater discharge point of building

Existing drainage and stormwater capture system should be adequate with little or no modification. There may be a risk that nutrients in the run-off could adversely effect the existing copper down pipes that may be part of the drainage system.


3.2.1 analySIS


Green Wall


Any green wall to this area would need to be a self supporting structure as the subject wall to the adjoining Victoria Hotel building is owned by others.

b) drainage considerations The existing drainage points to the east of the space is not currently in good condition (they are blocked with debris), but these could easily be reconfigured to take the additional run-off from a green wall irrigation system.

c) Shading/sunlight availability (aspect) and exposure

The space is in partial to full shade.

d) wind considerations Wind exposure is not significant.

e) Seasonal considerations Due to issues of leaf litter, deciduous species should be avoided.

f) height of building The height of the subject wall to the Victoria Hotel is approximately 18m. The height of the existing sculptural feature is 6m. The height of the area of wall visible from the ground floor Front Desk Waiting Area is 8.5m.

Figure 46. Potential location of green wall east of the Front Desk Waiting Area

Figure 47. A green wall could be located in the Skylight Area to the east of the Front Desk Waiting Area

Figure 48. Debris is collection at existing drain points

Figure 49. Ground floor storage vaults showing evidence of leakage from the skylight area above




3.2.1 analySIS


Green Wall

g) access for construction The distance from Little Collins Street to the roof space being 20m is within the reach of a large mobile crane. This would enable installation of large prefabricated sections of green wall support structure.

h) access for maintenance Access for maintenance could be from ground level using an elevated work platform from within the space. This would need to be a permanent item as access to remove and bring it in is limited.

i) Size of useable wall or façade area

Length of the potential wall is 9.0m. Full height is 18m. Visible height is 8.5m.

j) opportunities for site capture and storage of water for irrigation

The existing roof drainage, gutters and down pipes may provide efficient collection points to a water storage tank. There is an opportunity for site collected stormwater for irrigation re use to be stored in the existing Ground Floor storage vaults below the skylight area to the east of the Front Desk Waiting Area.

k) available space for plants to be grown from ground level upwards

There is potential to grow plants from the Ground Floor level/basement podium, along the western side of Victoria Hotel.

l) opportunities for more than one type of wall or façade. what type of green wall / facade (continuous/modular?)

There is an existing sculptural feature propped against the western wall of Victoria Hotel. The form of the existing sculptural feature lends itself to include an interpretation of the urban forest of Melbourne's CBD. This could be climbing plants. A system of modules and planters could be provided to sustain these climbing plants at the required heights. As this wall is owned by a different entity it is not allowable to attach new structures directly onto it.


Green Wall

m) access to utilities (water, electricity)

The light well is well serviced by potable water, electrical connections, and the provision of reticulated recycled water for irrigation would not be difficult (provided a storage tank is available).


The existing use of the building as a public asset and Council Office makes it conducive to being a location for a feature green wall. The opportunity is to improve the visual amenity and enhance the visitor experience to the City of Melbourne Front Desk Waiting Area.


The contribution of a green wall would not contribute to the building thermal performance.

p) factors associated with town planning, building permits, bca compliance and heritage issues

As the subject wall is owned by others, it will not be possible to mount directly to this. A free standing support structure will be required for the green wall.

As the space is not visible from the street, heritage values of the building external character would not be compromised.

As the space is lower than the Council Chambers, the risk of water damage to this important room is not present.

q) factors associated with noise No significant noise issues related to a green façade.

r) fire risk No significant fire issues related to a green façade.

s) Stormwater discharge point of building

Consideration will need to be given to recovery of run-off from green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green façade.




Figure 50. Potential area of geen roof Figure 51. Perimeter balustrade can be set back from the edge of the roof so as not to be visible from street level points

used for toilet flushing during winter which will significantly reduce the building’s water consumption.

The creation of a publicly accessible green roof will provide valuable green space in the centre of the city. The green roof will make this space signifiantly more aesthetically pleasing, and improve human comfort levels especially on warm and hot days.

The simple existance of a green roof up on the Melbourne Town Hall Administration Building will provide invaluable benefits in terms of raising awarenss of the issues of urban sustainability and the possibilities that our cities can realise through design innovation and integration of vegetation. These are values and messages that the City of Melbourne advocates.

Even if the cost / benefit payoff or value proposition for a publicly accessible green roof cannot be made to work, an extensive green roof could still provide tangible benefits if it was a working roof (that would provide thermal and biodiversity benefits), and only accessible to small groups and for maintenance.

green roofThe green roofs put forward in these findings are extensive green roofs. The level of provision of hardscape elements (decking, seating, shade etc) will be determined by whether public access is acheivable.

green wall / facadeThe green wall considered will be for visual effect so a fully vegetated modular or living wall will be required. This will be determined by the capacity and volume of water that can be harvested on site, which in turn will be influenced by the available area of roof stormwater run-off and the space for a storage tank.

3.2.2 fIndIngS

SuMMary

The potential development of the Melbourne Town Hall Administration Building provides an opportunity for inclusion of a green roof that will integrate with the overall building performance requirements. The challenge of successfully integrating a publicly accessible green roof on this building should not however be underestimated. The load capacity of the existing roof cannot accomodate a green roof without strucutral strengthening or bypassing with a new ‘floating’ structure.

The costs associated with bringing the load capacity of the roof up to that required for public access may not be prohibative in the context of the overall development costs, provided the full value of the benefits that the green roof can acrue be factored in. This includes both the additional amenity the green roof will provide, and the energy efficiencies that the green roof will provide in improved thermal performance and reduced heating and cooling loads.

If the redevelopment is to include refurbishment and upgrade of the exisitng lift, this can be extended to the roof top, then the structural augmentation of the roof need not be excessive when combined with a whole of building upgrade. The secondary considerations of compliant DDA and BCA provisions can all be addressed through design resolution.

The building thermal performance data that will enable inclusion of the green roof in the building ESD engineering and HVAC modelling may not yet exist, however enough data has been collected to verify the basic thermal performance in terms of a minimum R value, and roof temperature reductions on hot days.

The water storage that will be required to irrigate the green roof so that the plantings can tolerate the summer period, can also be


Green roof

a) Structural capacity The existing roof structure cannot carry an extensive green roof plus a limited number of people without strucutral augmentation. The amount of structural augmentation to the existing roof structure to accommodate a green roof will be dependant on whether the roof is accessible to the public or not.

As the roof is likely designed for 1.5 kPa (max.) for maintenance loading only, it would require a further 1.5 kPa of structural augmentation for 2 people per square metre (based upon 75kg per person) or 4.0 kPa for public access to satisfy the loading typically proposed for ‘areas where people may congregate’.

If it is to be accessible to the public then a live load of 3.0 kPa will be required for people, and an additional 1.5 kPa for the green roof self-weight (assuming it will be an extensive roof). This is a total of 4.5 kPa which exceeds the current likely capacity. There are two obvious solutions i) to bypass the existing roof structure by constructing a new (timber and steelwork frame) deck over and directly loading the columns and walls under or ii) Load directly upon the roof deck structure and strengthen accordingly by way of additional timber frame strengthening or additional steelwork beams.

If the roof is not to be accessible to the public then an extensive green roof could be accomodated however augmentation of the structure may still be required. If this was the case a 1.5 kPa live load allowance would need to be achieved (for people), and a 1.5 kPa live load for the green roof. This would allow limited numbers of people (up to 50 people over a 50 square metre area) to access the roof at a time. This would facilitate groups of 50 people at a time to access the roof for community awareness purposes, but would preclude groups larger than this. The opportunity exists to provide a floating green roof structure that would transfer loads to the main building structural walls.

Figure 52. Internal perimeter gutters drain the majority of roof area




Green roof

b) water proofing The existing water proof membranes are currently exposed and as a result their life cycle is diminished. The provision of a green roof as a protective covering to these will extend the design life of the membrane (due to the elimination of the deliterious effects of UV radiation from the sun) and reduce maintenance and replacement costs.

c) drainage The existing perimeter drainage system is suitable for integration with the green roof. The design must ensure free drainage to the existing down pipe collection points. It is important that the organic content of the green roof substrate be kept low (less than 10%) in order to ensure that nutrient loads in the stormwater run-off are kept to a minimum. Furthermore due to the likely presence of copper down pipes, nutrient levels should be kept low to minimise risk of corrosion.


The collection of roof run-off via the existing perimeter drainage system is relatively practical. This water could be diverted to a water storage in the vaults below the skylight area to the east of the Front Desk Waiting Area. Consideration for a green wall could be given to the area above this on the 1st Floor. This would replace (or be integrated with the existing sculptural piece. Refer wall assessment.

e) wind effects Due to the likely adverse wind effects caused by the urban canyon, the perimeter edge of a green roof will be vulnerable to damage. The design will require measures to mitigate these effects. This could take the form of setting the edge of the garden back from the edge of the roof.

Consideration should also be given to the selection of ballast material to the perimeter edge in terms of blow off wind speed, size of aggregate, and weight per square metre.

Consideration should also be given to selection of substrate composition, and plant species in terms of tollerance of wind effects.

f) building thermal performance There is an opportunity to reduce the summer heat loads on the building with the inclusion of an extensive green roof. The order of reduction in roof temperature is 25 degrees Celcius on hot days. This, combined with night time irrigation could significantly reduce internal building temperatures. The thermal resistance of the roof will also be improved, however there is insufficient research to ascribe a particular R value. Studies have shown however that this could be in the order of a 60% improvement.

This could reduce the energy required to cool the building, and could be considered in the future redevelopment design by taking into account the potential R value of the green roof in the building thermal modeling and heat load calculations. These factors could be considered in determination of building heat loads, and design of the new HVAC system as part of the redevelopment. The redevelopment is to acheive a 4.5 NABERS rating (whole building).

The report produced by Irwinconsult - City of Melbourne Administration Building Redevelopment ESD Opportunities Report 18 July 2012 Revision 1, includes addition of roof insulation as one of the ESD recommendations.

It is noted that this report also includes Urban Ecology - Green Roofs and Walls in its recommendations.


3.2.2 fIndIngS


Green roof






The air quality improvement potential of the green roof should also be considered from air intake plant in terms of removal of particulates, and lowering of roof temperatures on hot days.

j) visual amenity Inclusion of a green roof will be visible from a number of multi story buildings adjacent to the site including the buildings along the west side of Swanston Street and CH2 building.

k) urban food production Depending on the education and research agenda for the green roof, food production for public awareness purposes is possible. This may require marginally deeper substrate depths (greater than 200mm).

l) biodiversity and urban habitat

There is potential for the green roof to be a research subject on the factors associated with ecological values (eg habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.

m) building code compliance If the building is to be accessible to the public then disabled lift access is required. Exit travel distance to nearest single exit will need to not exceed 20m, if greater than this, a second exit will be required. Alternatively fire engineering measures could be considered if this is not practical.


Fire hose hydrant (30m hose with 10m hose stream) and hose reel (36m hose) coverage will be required.

The eventual design population would be determined by number of exits (exit width), live load of floor.


n) access for construction Crainage reach to the roof areas is acheivable with a large mobile crane, from Little Collins Street, however consideration of overhead powerlines and other obstructions will need to be included.

o) access for maintenance The existing fixed anchor points would be redundant if a new compliant safety barrier / perimeter balustrade could be provided.

The required offset from existing HVAC plant and equipment will need to be observed in the design of the green roof.




Green Wall

a) Structural capacity For heavier wall construction such as those in the region of 300kg per square metre. This structure would need to be free-standing steelwork frame restrained by the adjoining Victoria Hotel Wall.

b) on-site capture and storage of stormwater for irrigation re use

The run-off from a green wall would need to be recovered and re circulated through the stormwater storage and irrigation system to keep the planting alive.

Drainage and water proofing would need to be designed in order to ensure no adverse impacts on the spaces below or adjacent Victoria Hotel building.

c) wind effects The location for the potential green wall does not pose any issues with regard to wind effects.

d) building thermal performance The location for the potential green wall does not provide opportunities with regard to thermal performance.

e) noise The location for the potential green wall is not associated with with issues related to noise.

f) visual amenity Inclusion of a green wall will be visible from the entry area / reception, and has the potential to provide considerable and significant benefit to the communication of the City of Melbournes committment to green infrastructure intitiatives.

Figure 53. Potential location of green wall


3.2.2 fIndIngS


Green Wall

g) biodiversity and urban habitat There is potential for the green wall / facade to be a research subject on the factors associated with ecological values (eg habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.

h) building code compliance A green wall cannot be fixed to neigbouring buildings. The structural attachment and tie down and any other structural works will require a building permit that would need to look at public protection.

i) access for construction Crainage reach to the roof areas is acheivable with a large mobile crane, from Little Collins Street, however consideration of overhead powerlines and other obstructions will need to be included.

j) access for maintenance Access for maintenace would need to be via elevated work platform which would need to be stored in a conveinient location

k) heritage The proposal is unlikely to be problematic with regard to heritage signifiance.

lIttle collInS Street

Sw

an

Sto

n S

tre

et



3.3 St KIlda lIbrary

3.3.1 analySIS

overvIew

The building was built in 1973, designed by the award winning architect Enrico Taglietti. There was a major addition of the ‘book’ frontage by ARM architects in 1993.

The low and cantilevered ‘hovering’ form of the building provides an expanse of roof area that would be relatively easily accessible both physically and visually.


green roof The City of Port Phillip actively supports sustainability and is considering major improvements to this building, of which a proposed green roof is an important part.

The green proposition is also seen as an opportunity to convey practical ideas to the community so as to encourage their adoption on a domestic scale.

design emphasis

a) thermal

b) public access

c) aesthetic

d) wSud

e) food

f) research / teaching


Figure 55. Existing conditions drawings

EXISTING BASEMENT

WATER TANK

N




Green roof

f) Size of useable roof area The area available for a green roof is considerable (approximately 2,000 square metres). Some of this will need to be a non accessible perimeter sterile zone, set back for fall protection and wind protection. Provision will also be required of vertical visual screening elements (which could be green walls) to screen adjacent residential properties The remainder could be a combination of green roof (planted area) and hardscape (paving, decking, site furniture, shade elements etc.) depending on client and community preference and other project requirements.

g) height of building The building is single story with the ground to roof height of approximately 5m. This would require a ramp of approximately 80m to achieve a DDA compliant 1:14 ramp which is inappropriate. Accordingly a lift would need to be provided, which if glass would be a good replacement for the existing light well.

h) access for construction The north rear of the building has good access for crainage and construction activity. Access to the south front of the building is restricted due to the proximity of the busy Carlisle Street. Access to both east and west sides of the building is restricted by proximity of the existing adjacent residential buildings.

i) access for maintenance Due to the considerable proportion of the roof perimeter that has no fall restraint, either a physical barrier and set back to the edge of roof, or alternatively a fixed static line anchor system for maintenance OH&S compliance will need to be provided.


Green roof


The building structure comprises of a combination of insitu concrete walls and columns, supporting cantilevered roof forms. The roof structure is of light weight timber and steelwork construction. The roof deck is comprised of steel sheeting.

There is a concentration of structural load bearing capacity to the south due to the presence of internal walls. Provision of load bearing capacity to the north is more difficult without the imposition of additional columns.

The roof is likely designed for 1.5kpa (max.) for maintenance loading only. This has been based this upon experience of buildings of modern construction and exploratory works which confirmed that the roof structure is cold-formed steelwork purlins (lightweight construction). These buildings are typically designed very economically i.e. with no spare capacity.

b) water proofing Existing water proofing is achieved with the steel roof sheeting. The condition of the roofing material is variable. Significant areas are showing signs of corrosion. Large area have been recently replaced. Localised sealant works have been undertaken to a number of areas.

The light shaft has experienced repeated leakage events, and requires on going attention.

c) roof slope The roof is of a relatively flat pitch (approximately 1:60 or flatter). This is conducive to a green roof, and will make access and maintenance simple.


There are a number of different sun exposure zones to the roof, with some areas gently sloping to the north, and some gently sloping to the south. An area to the north is in semi shade cast by a large Eucalypt.

e) wind considerations There are a number of different wind exposure zones to the roof, with some areas gently sloping to the north, and some gently sloping to the south. The southern areas are protected from strong southerly winds by a 1.4m high parapet wall. The north and western sections of the roof have no wind protection. The eastern section of the roof is protected from winds by the adjacent residential development.

3.4 3.3 St KIlda lIbrary

3.4.1 3.3.1 analySIS

Figure 56. Light weight roof with sheet sheeting Figure 59. Some areas of the roof are shaded by existing large Eucalypt

Figure 57. Existing roof sheeting showing evidence of deterioration

Figure 58. Patching repair to existing roof sheeting Figure 60. Northern side of building addresses public open space




Green roof

j) potential for public access The site requires a public accessibility classification 9b (place of public entertainment) under the BCA. This deems that lift access must be provided.

Pending confirmation of max. height, a DDA compliant ramp could be provided for public access. An 80m length of ramp will be required to achieve a DDA compliant 1:14 ramp. There is sufficient space on the southern rear side of the building. This will take up some existing public open space which will need consideration.

If public access is to be provided then considerable extent of perimeter barrier or balustrading will be required. There is also an issue with over looking onto private habitable spaces on both the east and west sides of the building. Ideally there should be a set back of the accessible green roof area with a visual and physical barrier that will have the three fold advantage of providing safe access/fall protection, visual screening to adjacent habitable space, and protection from wind impacts on the garden edge (which is the most vulnerable to wind damage).


Pending on confirmation of the capacity and availability of the existing water storage tank in the basement car park, there is ample opportunity for site collection of stormwater for irrigation re use. The existing down pipes along the east and western elevations provide efficient collection points. The condition and capacity of the existing pump will need to be assessed for adequacy for irrigation re use.


The existing roof structural and building load bearing capacity lends itself to an extensive green roof. It is possible that a raised or mounded area be provided to the southern centre section of the roof to facilitate improved visual access of the living green roof from Carlisle Street and the St Kilda Town Hall.

Other areas could be extensive. Hardscape areas could be light weight decking (plastic), and vertical screening/barriers. These could be potentially green walls with integrated planting.


The existing evaporative cooling plant is redundant. The existing satellite receiver may be redundant. Other minor vents and services infrastructure can be retained. The green roof can be designed to integrate new and existing elements in a suitable and beneficial way in meeting the project objectives.

The roof is well serviced by potable water, electrical connections, and the provision of reticulated recycled water for irrigation would not be difficult (provided the existing storage tank is available for use).


3.3.1 analySIS

Figure 61. Down pipes presumed to connect to basement water tank

Figure 62. Area in basement where water tank is presumed to be located

Figure 63. Roof can be seen from Carlisle Street

Figure 64. Apartments adjacent to the east and overlook the roof

Figure 65. Residential rear patio adjacent to the west and overlooks to roof




Green roof


The existing use of the building as a public library makes it conducive to being a publicly accessible green roof. The opportunity to increase the amount of accessible green open space by providing this green roof is considerable.

The adjacency to Skye the at-risk-youth resource centre is also of benefit, with the potential to integrate the Green Roof for Youth (GR4Y) program such that these young people form part of the construction and maintenance team of the green roof.

Consideration will need to be given to the adjacent residential buildings in terms of overlooking. There are habitable spaces directly overlooking the roof on both the east and western sides. Both set backs and vertical screening will be required to alleviate this. On both the east and west side of there are opportunities to screen with ground based planting.


The existing roof has minimal insulation that is unlikely to be to current BCA standards. There is potential for the green roof to provide thermal performance improvements in terms of an increase in R value of the roof. This could reduce the energy required to cool the building. This should be considered in the future redevelopment design by taking into account the potential R value of the green roof in the building thermal modeling and heat load calculations.




This is not a heritage listed building however a Conservation Management Plan will govern any redevelopment.

r) factors associated with noise Proximity to adjacent residential properties will require an assessment of the noise impacts of public access, which due to lift access internally, will be restricted to day light hours only.

Figure 66. the adjacent residential apartments to the east will require visual screening

Figure 67. The existing parapet at the southern Carlilse Street side will afford fall protection

Figure 68. The existing light shaft is causing issues relating to water proofing, reducing thermal effieicny, and is not optimising light penetration


3.3.1 analySIS

Figure 69. Skys adjacent to the west




3.4.2 fIndIngS

SuMMary

The redevelopment of the St Kilda Library provides an opportunity for inclusion of a green roof that will integrate with the overall building performance requirements of the redevelopment project.

The costs associated with bringing the load capacity of the roof up to that required for public access may not be prohibative in the context of the overall development costs, provided the full value of the benefits that the green roof can acrue be factored in. This includes both the additional amenity the green roof will provide, and the energy efficiencies that the green roof will provide in improved thermal performance and reduced heating and cooling loads.

In order for the green roof to be accessible by the public, the redevelopment will need to include provision of a lift. Structural augmentation of the roof will also be required. Considerations of compliant DDA and BCA provisions can all be addressed through design resolution of features such as ramps, balustrades, set back of the garden from the roof edge and visual screening features.

The building thermal performance data that will enable inclusion of the green roof in the building ESD engineering and HVAC modelling may not yet exist, however enough data has been collected to verify the basic thermal performance in terms of a minimum R value and roof temperature reductions on hot days.

The water storage that will be required to irrigate the green roof so that the plantings can tolerate the summer period, can also be used for toilet flushing during winter which will significantly reduce the building’s water consumption. The existing roof drainage infrastructure and potentinal for a large water tank in the basement car park provide an oppertune set of circumstances to allow a relatively high capacity stormwater capture and storage system to be set up at relatively low cost. The creation of a publicaly accessible green roof will provide valuable green space in the centre of the city. The green roof will make this space significantly more aesthetically pleasing, and improve human comfort levels especially on warm and hot days.

The simple existance of a green roof on the St Kilda Library, will provide invaluable benefits in terms of raising awarenss of the issues of urban sustainability and encourage uptake of similar green roofs in residential settings within the municipality.

Even if the cost/benefit payoff or value proposition for a publicly accessible green roof cannot be made to work, an extensive green roof could still provide tangible benefits if it was a working roof and only accessible to small groups and for maintenance.

green roof The green roofs put forward in these findings are extensive green roofs. The level of provision of hardscape elements (decking, seating, shade etc) will be determined by whether public access is acheivable and budget factors.


Green roof

a) Structural capacity The existing roof cannot carry an extensive green roof of 1.5kPa plus a limited number of people without structural augmentation. The amount of structural augmentation to the existing roof structure to accommodate a green roof will be dependant on whether the roof is accessible to the public or not.

If it is not to be accessible to the public then a maintenance live load of 1.5kPa will be required for for 2 people per square metre (based upon 75kg per person), and an additional 1.5kPa for the green roof (assuming it will be an extensive green roof). This would allow limited numbers of people (say up to 50 people) to access the roof at a time. This would facilitate groups of 50 people at a time to access the roof for community awareness purposes, but would preclude groups larger than this.

Alternatively an intensive green roof that included paving/decking; shade structures; site furniture etc, would require in the order of 10.0kPa. It would require a further or 4.0kPa to satisfy public loading typically proposed for ‘areas where people may congregate’.

This is a total of 4.5kPa for no public access, to 14.0kPa for public access, both of which exceeds the current capacity. To achieve these loads it will be neccessary to provide a new suspended deck structure to support the green roof and transfer the loads directly to the building walls below, thereby bypassing the roof deck structure. Alternatively, if the proposal was to load the exisitng roof deck directly, the degree of strengthening would be exccessive and as such we would suggest that it is not commercially viable.

Any structural augmentation will need to be achieved without the need for additional internal columns so that the architectural intergrity of the internal spaces be maintained.

b) water proofing The existing water proofing is provided by the roof sheeting which is in various states of deterioration. The provision of a green roof as a protective covering to these will extend the design life of the membrane and reduce maintenance and replacement costs.



The collection of roof run-off via the existing perimeter drainage system is relatively practical. This water could be easily diverted via the existing roof run-off down pipes to the existing water storage tank in the basement car park. There is an existing pump which may be suitable for reticultation to the irrigation system of the green roof.

e) wind effects In the absence of any existing parapet, consideration of design against wind action should be given in the green roof. This could take the form of detailing of the edge restraint, and consideration of potential twin vortex effects.




Green roof

f) building thermal performance

There is an opportunity to reduce the summer heat loads on the building with the inclusion of an extensive green roof. The order of reduction in roof temperature is 25 degrees Celcius on hot days. This, combined with night time irrigation will significantly reduce internal building temperatures.

The thermal resistance of the roof will also be improved, however there is insufficient research to ascribe a particular R value. Studies have shown however that this could be in the order of a 60% improvement.

These factors could be considered in determination of building heat loads, and design of the new HVAC system as part of the redevelopment.






The air quality improvement potential of the green should also be considered from air in take plant in terms of removal of particulates, and lowering of roof temperatures on hot days.

j) visual amenity Inclusion of a green roof will be visible from the entry podium of the Town Hall building on the south side of Carlisle Street.

k) urban food production Depending the the education and research agend for the green roof, food production for public awareness purposes is possible. This may require marginally deeper substrate depths (greater than 200mm).

l) biodiversity and urban habitat

There is potential for the green roof to be a research subject on the factors associated with ecological values (eg habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.


3.3.2 fIndIngS


Green roof

m) building code compliance If the building is to be accessible to the public then disable lift access will be required. Exit travel distance to nearest single exit will need to not exceed 20m, if greater than a second exit will be required. Alternatively fire engineering measures could be considered if this is not practical.


Fire hose hydrant (30m hose with 10m hose stream) and hose reel (36m hose) coverage will be required.

The eventual design population would be determined by number of exits (exit width), live load of floor.


n) access for construction Crainage reach to the roof areas is acheivable with a large mobile crane, however consideration of overhead powerlines and other obstructions will need to be included.

o) access for maintenance The existing fixed anchor points would be redundant if a new compliant safety barrier / perimeter balustrade could be provided.

The required off set from existing HVAC plant and equipment will need to be observed in the design of the green roof.

p) access for the public Considerations and appropriate design measures relating to loading, disabled access and fire egress, will be required, in order that public access be provided in a cost effective manner.

A perimeter balustrade of minimum 1.2m height will be required, set back from the edge of the roof.

q) heritage If structural augmentation is required it will need to be achieved without additional internal coloumns in order that the architectural integrity of the internal spaces be maintained.



3.5 222 banK Street, South Melbourne

3.5.1 analySIS

design emphasis

a) thermal

b) aesthetic

c) wSud

d) biodiversity


overvIew

The existing building was constructed in 1967, and subsequently refurbished in 1991. The tennants are comprised of a number of community arts organisations.


green wall / facadeThe impetus for consideration of a green facade comes out of the DDA compliance issues associated with the building, as well as the revitalisation opportunies arising out of the Emerald Hill Master Plan.

Both the City of Port Phillip and the tennants support the initiative for a green façade. The green façade could serve multiple benefits and reinforce the sustainability agenda of Council.

green roof

There is also the opportunity for a ‘working’ green roof - which could provide thermal benefits as well as contribute to stormwater management and the site’s biodiversity values. This has been included not as part of the core study but as a suggestion for future consideration. All comments relating to the green roof should be considered in light of this.

Figure 71. Existing condition

PotentIAL LoCAtIon For

BAsement WAter tAnK

PotentIAL LoCAtIon For

Ground BAsed PLAntInG

POTENTIAL SUPPORT FOR

GREEN FACADE

POTENTIAL LOCATION

GREEN FACADE




Green façade

h) access for maintenance Access for maintenance could be from ground level or roof level.


There is potential to utilise a portion of the entire south and east elevations (subject to internal shading and view requirements).


There is the potential to provide significant above floor water storage tanks in the basement car park, that could easily be connected to the roof drainage system.

There is an existing water storage to the rear of the Town Hall across the road which could be reticulated to 222 Bank Street.


There is potential to grow plants from the ground level along the southern and eastern sides of the building at the interface between the basement car park and the foot path. This space is currently under utilised.

l) opportunities for more than one type of wall or façade. what type of green wall / facade (continuous / modular?)

The configuration of spandrel panels, and glazing lends itself to a hybrid of continuous ground planting, modular, and cable based planting systems.


Reticulation of irrigation is easily facilitated by the existing building fabric.


Green façade


The building structure is comprised of insitu concrete frame and slab. It appears that the south and eastern façades have been augmented with decorative circular hollow section steel columns with steel box junction panels and the façade spandrels. These are not load bearing but have some capacity to support a green façade.

The roof is likely designed for 1.5kpa (max.) for maintenance loading only. This has been based this upon experience of buildings of modern construction and exploratory works which confirmed that the roof structure is cold-formed steelwork purlins (lightweight construction). These buildings are typically designed very economically i.e. with no spare capacity.

b) drainage considerations The roof drains to perimeter gutters which then drain via down pipes to street level. These are directed to the east side of the basement car park and could be easily gathered at a tank if it was located at the south end of the basement car park under the existing entry ramp.


The southern and eastern elevations are in semi to full shade which may limit species selection to those that are tolerant of these conditions.

d) wind considerations The building is located on a high point in the local area and the southern elevation would be subject to reasonably strong cold southerly winds. The eastern elevation is somewhat protected from strong winds.

e) Seasonal considerations Given the shady exposure, it would be advantageous to consider deciduous species to maximise winter solar access to the building for both light and warmth.

f) height of building The building being two stories high does not pose too many problems in terms of access for maintenance. There is a high potential for benefit visual amenity values to the local area.

g) access for construction The site has easy access for cranes during construction.


3.4.1 analySIS

Figure 72. Existing entry stairs in need of redevelopment to rationalise DDA access to the building

Figure 73. Existing decorative circular hollow section steel columns with steel box junction panels and the façade spandrels.

Figure 74. Area beneath existing entry stairs and ramp to the south provides an opportunity for the location of a water storage tank

Figure 75. View to the east from inside level 2 board room




Green façade


The existing use of the building is community arts offices leased from Council. This would likely facilitate implementation of a green façade, provided adequate support from tenants is achieved.


Existing cooling system is evaporative roof mounted plant, ducted to internal rooms.

The heat loads on the southern and eastern façades are not significant, so there is little thermal building performance advantage from a green façade. The heating system is comprised of approximately 7 no. split unit reverse cycle air conditioners. The windows currently are coated with a tinted film which reduces light penetration into the building and is unlikely to assist with building thermal performance. There is little or no direct sun incidental on the glazed elevation, there is little advantage to be gained with respect to winter heating efficiency from a green façade.


As the building has no heritage significance, there is no issues related to heritage.

The clear sight lines along the southern and eastern footpaths will need to be maintained, with head clearances of minimum of 2.4m to ensure DDA compliance.




Consideration will need to be given to recovery of run-off from a green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green façade.

Figure 76. Eastern facade showing spandrel and decorative circular hollow section steel columns with steel box junction panels and the façade spandrels.

Figure 77. Any green facade will need to maintain clear lines of sight and required head clearances to comply with DDA access. Opportunities also exist to provide greening to car park undercroft


3.4.1 analySIS


Green roof


The building structure is comprised of insitu concrete frame and slab. The roof structure is of light weight timber construction with a load bearing capacity of 1.5kPa for maintenance purposes. The roof deck is comprised of steel sheeting.

b) water proofing Existing water proofing is achieved with the steel roof sheeting. The condition of the roofing material is generally very good with little or no signs of corrosion or repairs. Some minor sealant works have been undertaken at the perimeter gutters. The light well pavement does not appear to be of a water proof material and has been coated in recent times. A leak at the doorway has been addressed with a localised patch to make the threshold water proof.

c) roof slope The roof is of a relatively flat pitch (approximately 1:80 or flatter). This is conducive to a green roof, and will make access and maintenance simple. The ridge line is central to the building running from east to west.

d) Shading/sunlight availability (aspect) and exposure

The roof has full sun exposure with little or no shading.

e) wind considerations The roof is generally fully exposed to prevailing winds. Although the building is only two stories high, its positioning at the top of the neighborhood rise makes the roof susceptible to all prevailing winds. The pitch of the roof from the central east/west ridge provides a low parapet which will provide some degree of wind protection to the north and southern edges of the roof. The east and western edges will require consideration of wind effects.

f) Size of useable roof area The area available for a green roof is considerable. Some of this is taken up by the existing mechanical plant.

g) height of building The building is two story.

h) access for construction Access to the roof for construction will be relatively easy along the east and southern adjoining streets.

Figure 78. The roof offers an opportunity for a working green roof Figure 79. Existing roof drainage points could easily cater for green roof drainage

green roof

We have also considered the opportunity for a ‘working’ green roof - which could provide thermal benefits as well as contribute to stormwater management and the sites biodiversity values.




Green roof


The potential for the green roof to provide thermal performance improvements in terms of an increase in R value of roof insulation is high. This could reduce the energy required to cool the building. This should be considered in the future redevelopment design by taking into account the potential R value of the green roof in the building thermal modeling and heat load calculations.




The building is not of heritage significance. Reddo to comment on building permitting.

r) factors associated with noise As provision of public access is unlikely, the proximity to adjacent residential properties will not result in noise impacts.


Due to absence of parapet walls of adequate height, fall protection will need to be provided. This could take the form of a fixed lanyard anchor system.



Consideration will need to be given to the recovery of run-off from the green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green roof.


Green roof

i) access for maintenance Access for maintenance is provided with the existing roof ladder. A DDA access lift is being considered as part of the redevelopment plans, which if provided would allow for improved access.

j) potential for public access DDA compliant public access will be difficult without provision of a new lift to roof level. Public loading will need to be considered.


There is the potential to provide significant above floor water storage tanks in the basement car park, that could easily be connected to the roof drainage system.

There is an existing water storage to the rear of the Town Hall across the road which could be reticulated to 222 Bank Street.


The existing roof structure and building load bearing capacity lends itself to an extensive green roof. The existing steel access walk ways could be retained for maintenance.


"The existing roof mounted HVAC systems are generally consolidated into a single area, with a small amount of equipment located away from this are in the center of the roof. The roof is well serviced by potable water, electrical connections, and the provision of reticulated recycled water for irrigation would not be difficult."

n) existing use/s of building (e.g. commercial, residential)

Existing use of building is community arts offices leased from Council. This would likely facilitate implementation of a green roof provided adequate support from tenants is achieved.

Figure 80. Existing roof ladder is not suitable for public accesss Figure 81. Existing HVAC plant and equipment Figure 82. Existing HVAC plant and equipment


3.4.1 analySIS



Figure 83. Visualisation of possible arrangement of green facade from the south east

Figure 84. Visualisation of possible arrangement of green facade from the inside.

Figure 85. Section of possible arrangement of green facade showing water tank and irrigation reticulation

The integration of greening to this building is a tantilising prospect given the building’s history and current use and the interest and support that is present in the stakeholders. The existing building fabric is configured such that the addition of the required infrastructure in terms of both physcial support (ie a garden substrate) and the horticultral requirements (i.e. an irrigation system), could be achieved with relative ease.

The presence of decorative steel struts provide a framework for fixing a green wall / facade to the façade. The existing roof drainage system could easily be directed to a new water storage that could be provided to the southern end of the basement car park, as part of the proposed DDA access works.

The potential location of a green façade being on the eastern and southern sides of the building mean that it would not contribute to the thermal performance of the building.

Notwithstanding this the visual impact of a vegetated façade would be significant as it would provide a highly visible presentation to Bank Street, enhanced by it adjacency to the Town Hall, and prominance at the top of the local rise of the South Melbourne hill.

There is also a significant visual impact of the green façade when viewed from the internal spaces of the building, which could add to the property value if Council were to sell the building.

green wall / facade

Given the issues associated with internal light levels to the building, a fully vegetaed façade would not be suitable. An alternative to this is a system whereby the green façade is comprised of vegetated vertical fins set at right angles to the façade. these could easily be mounted to the decorative steel struts. Fully planted modules could be positioned at the upper, middle, and lower spandrel panels. Steel cables could be used to support climbing and trailing plants that, if deciduous, would provide a cool green outlook in summer, but allow maximum winter light into the building.

green roof

A green roof could also provide tangible benefits in terms of the building’s thermal performance. This could be a working roof, not accessible to the public, and only accessible to small groups and for maintenance.


3.5.2 fIndIngS


Green façade

a) Structural capacity Although the remodelled façade structure is decorative, it will have some load bearing capacity depending upon the fixings at the junction and the connections to the concrete spandrel panels. It is likely to support a green wall with lightweight framing with nominal augmentation of the existing structure.


The existing roof drainage system could easily be configured to direct roof run-off into a water storage at the southern end of the basement car park.

c) wind effects The supporting structure of the green façade could be designed to accomodate the wind loads. Plant species selection would also need to consider wind effects in terms of water loss in transpiration, as well as ability to tollerate wind shear.

d) building thermal performance As the subject building elevations are on the southern and eatern sides, there would be little contribution to building thermal performance in summer in terms of cooling.

e) noise N/A

f) visual amenity There is great potential for a green façade to contribute positively to the presentation of the building to the street, and make a strong statement regarding green infrastructure and ESD in the City of Port Phillip.

g) urban food production The green façade could conceivably carry edible plants, however this may impact on the visual qualities.

h) biodiversity and urban habitat There is potential for a green façade to provide habitat values for birds and insects.

i) building code compliance Any structural works will require a building permit that would need to consider public protection.

j) access for construction Crainage reach to the façades is acheivable with a mobile crane. Consideration of overhead powerlines and other obstructions will need to be included.

k) access for maintenance Maintenance access would need to be provided from either top down roof access, on-ground up mobile work platform or scissor lift.

This would need to be anywhere from 2 to 6 times per year, depending on the final planting design.

l) heritage As the building is not heritgae listed there would be no issues relating to this.




3.4.2 fIndIngS


Green roof

a) Structural capacity The existing roof cannot carry an extensive green roof of 1.5kPa plus a limited number of people without structural augmentation.

If it is not to be accessible to the public then a maintenance live load of 1.5kPa will be required for 2 people per square metres (based upon 75kg per person), and an additional 1.5kPa for the green roof (assuming it will be an extensive green roof). This would allow limited numbers of people (say up to 50 people) to access the roof at a time.

This is a total of 4.5kPa which exceeds the current capacity. To achieve these loads it will be neccessary to provide a new suspended deck structure to support the green roof and transfer the loads directly to the building walls below, thereby bypassing the roof deck structure. Alternatively, if the proposal was to load the exisitng roof deck directly, the degree of strengthening would be exccessive and as such we would suggest that it is not commercially viable.

b) water proofing The existing water proofing is provided by the roof sheeting which is currently in reasonable condition. The provision of a green roof as a protective covering to these will extend the design life of the membrane and reduce maintenance and replacement costs.



The collection of roof run-off via the existing perimeter drainage system is relatively practical. This water could be easily diverted via the existing roof run-off down pipes to a new water storage tank in the basement car park.

e) wind effects In the absence of any existing parapet, consideration of design against wind action should be given in the green roof. This could take the form of detailing of the edge restraint, and consideration of potential twin vortex effects.

f) building thermal performance There is an opportunity to reduce the summer heat loads on the building with the inclusion of an extensive green roof. The order of reduction in roof temperature is 25 degrees Celcius on hot days. This, combined with night time irrigation will significantly reduce internal building temperatures.

The thermal resistance of the roof will also be improved, however there is insufficient research to ascribe a particular R value. Studiies have shown however that this could be in the order of a 60% improvement.





Green roof


If photo voltaic panels were to be provided on the roof for generation of electrical energy for the building, their performance on hot days could be significantly improved due to the cooling effect of a green roof (up to 25 degrees Celcius)



j) visual amenity A green roof would not be visible from street level.

there may be some visual access from the top level of the adjacent Town Hall building, as well as from the nearby multi level housing commission apartments.

k) urban food production Depending the the education and research agenda for the green roof, food production for public awareness purposes is possible. This may require marginally deeper substrate depths (greater than 200mm), with an associated increase in loads on the roof structure.

l) biodiversity and urban habitat There is potential for the green roof to be a research subject on the factors associated with ecological values (eg habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.

m) building code compliance The required off set from existing HVAC plant and equipment will need to be observed in the design of the green roof.


o) access for maintenance Fixed anchor points would be required. Alternatively compliant safety barrier / perimeter balustrade could be provided.

p) access for the public It is not recommended that the green roof be publicly accessible due to the nature of the building tennancies.

q) heritage There are no hertitage issues associated with this building.



3.6 north fItzroy coMMunIty hub

3.6.1 analySIS

design emphasis

a) public access

b) aesthetic

c) thermal

d) food?

e) wSud


overvIew

This building is unbuilt, but well into the community consultation phase. It is intended to be a 6 star Greenstar development with a number of green roofs.

gardenS for conSIderatIon

green roofThe current design indicates there is an outdoor community gathering space/green roof on level 3. There is also the potential for a top level ‘working’ green roof, that would provide thermal benefits as well as contribute to the sites biodiversity values

green wall / facadeDue to the orientation of the site towards the north and the requirement for a large occupiable space with an outlook to this direction, the challenge is to maintain visual connectivity to the street scape, without compromising good passive thermal design Accordingly, there is an opportunity to use façade greening to contribute to the building’s thermal performance.

Figure 87. Proposed design

Figure 88. Existing site from the north Figure 89. Existing site




Green roof


From review of the drawings as supplied, it appears that the building structure comprises concrete framed construction. Given the spans involved in the building we have assumed that the green roof deck will also be concrete. If this assumption is correct then a reasonable loading capacity could be designed as in excess of 4.0 kPa to accommodate public loading.

This site requires a public accessibility classification 9b (place of public entertainment) under the BCA. This deems that lift access to the green roof must be provided for fire egrees requirements.

b) water proofing Water proofing will need to be considered in the detailed design.

c) roof slope The roof appears to be of a relatively flat pitch (approximately. 1:80 or flatter). This is conducive to a green roof, and will make access and maintenance simple.


The roof is partially protected from full sun exposure with some areas in part shade.

e) wind considerations The roof is partially protected from prevailing wind. The western edge will require consideration of wind effects.

f) Size of useable roof area The area available for a green roof is considerable.


3.5.1 analySIS


Green roof

g) height of building The building is three story. The green roof is on the second level.

h) access for construction Access to the roof for construction will be relatively easy along Best Street (potentially partial road closure required).

i) access for maintenance Access for maintenance can be provided with stair and lift access.

j) potential for public access DDA compliant public access can be provided with the inclusion of a lift to green roof level. Public loading will need to be considered in the structural design of the roof deck.


If practical the roof drainage design should direct roof run-off to under ground water storage tanks in Best Street.


The current design includes a combination of external decking and green roof areas to the second floor. Consideration should be given to combining the areas of hard and soft elements to improve the amenity of the spaces. The current also design shows trees which will need particular consideration in terms of weight and wind tolerance, as well as irrigation water demand.

If trees were to be provided they would need to be positioned over columns or the loading capacity of the roof increased to 15kPa.

Figure 90. Existing site from the north Figure 91. Section through proposed building showing potential green roof locations Figure 92. Potential location of in ground water storage tank

POTENTIAL LOCATION FOR IN GROUND

WATER TANKBEST ST

ST GEORGES RD




Green roof


There does not appear to be any plant or equipment required to the green roof area. It is assumed that this will be located on the upper level roofs. This will need to be confirmed during design development.

The green roof level will need to be serviced by irrigation water, and electrical connections.


The use of the building as a public library and community hub makes it conducive to being a publicly accessible green roof. The opportunity to increase the amount of accessible green open space by providing this green roof is considerable.

From review of Option 1 sections it appears that the overlooking of the residential buildings to the east of Best Street will not be an issue.


The potential for the green roof to provide thermal performance improvements in terms of an increase in R value of roof insulation is present. This could reduce the energy required to cool the building. This should be considered in the design by taking into account the potential R value of the green roof in the building thermal modeling and heat load calculations.




TBC

r) factors associated with noise Proximity to adjacent residential properties will require an assessment of the noise impacts of public access particularly at night.


A parapet or balustrade of minimum weight will need to be provided for fall protection. This would need to be 1.0m high under the BCA, however may ned to be higher to satisfy Safety in Design requirements for maintenance.

Figure 93. Proposed design from the north


Green roof



Consideration will need to be given to recovery of run-off from green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green roof.

Figure 94. Best St could accomodate an in ground water tank

Figure 96. Existing site Figure 95. Existing site


3.5.1 analySIS


Green façade


From review of the drawings as supplied, it appears that the building structure is comprised of concrete wall panels, with a glass curtain wall. It is unclear what the structural configuration of the glass curtain wall is.

b) drainage considerations If practical the roof drainage design should direct roof run-off to an under ground water storage tank in Best Street.


Given the western orientation of the main library space, consideration could be given to shading the glass curtain wall with planted louvers. This will reduce the solar gain in summer, and therefore heat loads on the building, and energy demand for airconditions.

Consideration could be given to using deciduous plants on these louvers such that winter solar gain can be maintained reducing the heating energy demand during the cold parts of the year.

The merit of including a green façade on the east elevation from a thermal performance point of view is dubious. There may be merit from a visual amenity and aesthetic point of view, however consideration should be given to the reduction in solar gain during winter which would increase the heating energy loads.



Figure 97. Proposed building section showing potential location for green facade


Green façade

d) wind considerations The western façade is exposed to the prevailing winds which if a green façade was installed would require consideration of irrigation water demand.

e) Seasonal considerations Refer Item 3.5.24


g) access for construction The site has easy access for cranes for construction.



There is potential to utilise a portion of the entire western elevations (subject to internal shading and view requirements).


There is the potential to direct roof run-off to an under ground water storage tank in Best Street.


There is potential to grow plants from the ground level along the southern and eastern sides of the building.


The configuration of spandrel panels, and glazing lends itself to a hybrid of continuous ground planting, modular, and cable based planting systems.


Reticulation of irrigation is easily facilitated by existing building fabric.


Green façade


The existing use of the building is community arts offices leased from Council. This would likely facilitate implementation of a green façade, provided adequate support from tenants is achieved.


The northern orientation of the building and east / west facing elevations being fully glazed provide a challenging condition for passive building thermal design.

The installation of a green facade on these elevations could reduce summer heat loads and winter heat loss considerably.


A green facade would not pose any significant issues relating to Town Planning approval provided the BCA requirements are satisfied in term of strucutral design. DDA access along pedestrian areas would need to be maintained in terms of sight lines and head clearances if facade elements are located near circulation paths.

q) factors associated with noise A green façade to the west of St Georges Road elevation would contribute to the reduction of traffic noise impacts.



Consideration will need to be given to the recovery of run-off from the green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green façade.


3.5.1 analySIS

Figure 98. Proposed building level 1 plan showing potential location for green facade

POTENTIAL LOCATION

GREEN ROOF

BEST ST

BEST ST

ST GEORGES RD

ST GEORGES RD

POTENTIAL LOCATION

GREEN FACADE

POTENTIAL LOCATION

GREEN FACADE




3.6.2 fIndIngSAs this building has not yet been constructed, and it is still in design and consultation phase, the potential for green roofs, walls and façades is great.

The current proposal identifies a publicly accessible green roof to level 3, and also mentions the potential for a roof top green roof. It does not include a green façade, however the 3D renders of the Schematic Design Option 1 show large expanses of glazing to the north facing façades which would have a high heat load that would require some form of shading, or expensive heat reflecting glass in order to achieve the stated target 6 star Greenstar rating.

The scope for the green roofs and façades to be developed and integrated into this design is considerable.

green roof

A publicly accessible green roof on level 3 would contribute significantly to the project in terms of a space that could facilitate a flexible program which would sit well with the Community Hub concept. If the floor plate structure was to be of concrete construction then the additional cost premium would not be excessive.

An extensive green roof could be accommodated on a light weight roof structure to the level 3 roof with loads transferred to the main structure without significant additional cost compared to a conventional roof if it was designed into the project during the design development phase.

Drainage, stormwater capture and storage could all be designed in without significant additional cost, with surplus water during winter being used for toilet flushing.

The thermal performance of the building would be enhanced by both green roofs, especially the upper roof if it could be designed to cover a significant area. This would be of benefit to both summer cooling loads, and winter heat loads.

green wall / facade

A green façade configured to provide shading to the significant area of glass curtain wall would contribute greatly to overall building thermal performance. This could be designed to provide visual interest and access into and out of the building, while at the same time reducing the heat loads. If designed in an integrated manner it would also contribute to the architecture quality of the building.

determining Parameter Comments

Green roof

a) Structural capacity The design load for the green roof should be such that a live load 7.5 kPa can be accomodated to account for public access and the green roof. Heavier elements such as hardscape, shade structures and site furniture of 10 kPa may be required in some areas (depending on the final design outcomes).

It is recomended that a concrete roof deck structure be employed to accomodate these loads.

b) water proofing If designed from the begining as an integrated system the green roof will assit with prolonging the life of the water proof membranes without influencing risk of water ingress.

c) drainage The design must ensure free drainage to the existing down pipe collection points.


Roof run-off should be directed into an underground irrigation water storage beneath Best Street.

Surplus water will be available for toilet flushing in winter when the irrigation system will not be required to run at significant capacity.

e) wind effects The design of the green roof will need to consider wind action. This is especially pronounced at the edges of the green roof. Some form of parapet protection or edge restraint will need to be provided depending on the results of detailed wind assessments.

f) building thermal performance The green roofs will provide improvements in the buildings thermal performance in terms of an increase in R value, and a reduction of roof surface temperatures.

The order of reduction in roof temperature is 25 degrees Celcius on hot days. This, combined with night time irrigation will significantly reduce internal building temperatures.

The thermal resistance of the roof will also be improved, however there is insufficient research to ascribe a particular R value. Studies have shown however that this could be in the order of a 60% improvement.


g) noise A green roof would contribute to the reduction of traffic noise impacts to the internal spaces of the building.


If photo voltaic panels were to be provided on the roof for generation of electrical energy for the buildin, their performance on hot days could be significantly improved due to the cooling effect of a green roof (up to 25 degrees Celcius)






Green roof

j) visual amenity A green roof would not be visible from street level.

There may be some visual access from the top level of the adjacent Town Hall building, as well as from the nearby multi level housing commission apartments.

k) urban food production Depending the the education and research agenda for the green roof, food production for public awareness purposes is possible. This may require marginally deeper substrate depths (greater than 200mm), with an associated increase in loads on the roof structure.

l) biodiversity and urban habitat There is potential for the green roof to be a research subject on the factors associated with ecological values (eg habitat for invertibrates), with the inclusion of insect traps and monitoring of species occurances.

m) building code compliance The required off set from existing HVAC plant and equipment will need to be observed in the design of the green roof.


o) access for maintenance Fixed anchor points would be required. Alternatively compliant safety barrier / perimeter balustrade could be provided.

p) access for the public TBC

q) heritage N/A


3.5.2 fIndIngS


Green Façade

a) Structural capacity The new building façade can be designed to accommodate green walls as discusssed. The current design will need to be reviewed accordingly as the current Client brief is not known.


The system that could be implemented for the green roof could be expanded to provide irrigation water storage capacity for a green façade.

c) wind effects The supporting structure of the green façade could be design to accomodate the wind loads. Plant species selection would need also to consider wind effects in terms of water loss in transpiration, as well as ability to tollerate wind shear.

d) building thermal performance Building envelope thermal transfer can be reduced by inclusion of a green facade with a reduction of up to 40% provided at least 50% of the facade is shaded by vertical greening.

A green facade could produce a reduced heat gain in summer by up to 2.4W/m2 and heat loss of up to 3.6 W/m2 in winter. This translates to a reduction in energy consumption of 0.6 kWh based on a 2.5 Star NABERS Performance.

e) noise N/A

f) visual amenity There is great potential for a green façade to contribute positively to the presentation of the building to the street, and make a strong statement about green infrastructure and ESD in the City of Yarra.





k) access for maintenance Maintenance access would need to be provided from either top down roof access, of ground up modile work platform / scissor lift.


l) heritage N/A



3.7 fItzroy town hall

3.7.1 analySIS

overvIew

This Victorian era building, is of masonry construction and has significant heritage values. The main entry has been located to the western courtyard away from the eastern ceremonial steps on Napier Street. As a result, this entry is experienced as a ‘backdoor’ and has a poor public presentation.

gardenS for conSIderatIon

green wall / facadeThese recommendations are based on the opportunity for vertical greening to a number of walls to this building.

The new lift shaft structure has provided a higher quality architectural entry statement. The cladding to this being 100% glazing does pose a problematic thermal performance issue with the existing refrigerated airconditioning which runs at full capacity to cool a space that is only temporarily occupied.

The northern and southern wings of the building, although of some heritage value provide opportunities to contribute to an improvement of the visual quality of an under utilised courtyard.

design emphasis

a) thermal

b) aesthetic


Figure 100. Existing conditions ground level plan Figure 101. Existing conditions roof plan

Figure 102. Existing conditions section Figure 103. Existing conditions photo

POTENTIAL LOCATION

FOR GREEN FACADE

POTENTIAL LOCATION

FOR GREEN FACADE

POTENTIAL LOCATION

FOR GREEN FACADE




Green façade / Wall


The original building structure is comprised of masonry walls and internal masonry columns. The new entry and lift well is comprising steelwork frame supporting glass panels. It is likely that the steelwork frame has a capacity to support a new green wall in the region of 150kg/square metres.

b) drainage considerations The southern wing roof drains to perimeter gutters which then drain via down pipes to ground level. These could be easily gathered at a tank if it was located at the north side of the southern wing.

c) Shading / sunlight availability (aspect) and exposure

The new lift well has a western aspect which is exposed to the full afternoon summer sun. The north elevation of the southern wing is exposed to near full sun. The south elevation of the northern wing is in near full shade, with only very late afternoon summer sun.

d) wind considerations The three subject walls form a courtyard and as such wind exposure is not significant.

e) Seasonal considerations It would be advantageous to consider deciduous species to the lift well façade to maximise winter solar access to the lift well for both light and warmth.

f) height of building The building being four stories high does not pose too many problems in terms of access for maintenance. There is a high potential for the benefit of visual amenity values to the local area.


h) access for maintenance Access for maintenance could be achieved from ground level using a elevated work platform.


3.6.1 analySIS

Figure 104. Existing gazed lift well is the potential location for a green facade

Figure 105. Existing contsruction detail Figure 106. South wing north elevation could accomodate a greeen facade Figure 107. Cloister to south wing could accomodate a water tank




There is potential to utilise a portion of the west elevation to the lift well, and inward courtyard facing elevation of the northern and southern wings. The west elevation of the north wing could also be considered.


There is the potential to provide a significant above ground water storage tank in the northern portico of the southern wing, provided this area is not currently utilised.


There is potential to grow plants from the ground level along the west side of the new lift well atop the elevated plinth.


The configuration of steel columns glazing on the new lift well, lends itself to a hybrid of continuous ground planting, modular, and cable based planting systems. The masonry walls of the north and south wings are suited to modular green walls, of cable based planting systems.


The existing sewer and roof plumbing pipe work being external to the building provides some restriction.


Existing use of building is Council and Police offices. This would likely facilitate implementation of a green façade, provided adequate support from tenants is achieved. Building ownership of the southern wing will need to be confirmed.






The lift well is currently cooled with a refrigerated split unit at level 3. Anecdotal information is that this unit is at capacity and may not effectively cool the space in summer due to the large amount of west facing glazing.


Victorian Heritage Register: H0147. Significance: Most intact and exemplary High Victorian building. Designer by eminent George Johnson.




Consideration will need to be given to the recovery of the run-off from green façade for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green façade.

Figure 108. View from above of south wing north elevation Figure 110. View from above of north wing south elevationFigure 109. Existing plinth to lift well is suitable for ground based planting


3.6.1 analySIS




3.7.2 fIndIngSThe new lift well space as a recent and modern architectural treatment to this historically significant Victorian building lends itself to vertical greening both from a visual and thermal performance point of view.

green wall / facade

The structure is of a type of construction that could accommodate easily the loads that a green façade would impose on it. The glass cladding system could be left intact and a green wall / facade installed directly to the structural steel supports which are exposed.

The southern wing has the potential to support a green wall which would provide both visual and thermal performance benefits to this building.

The portico to the southern wing could accommodate irrigation water tanks fed from the existing down pipes of this building.

The northern building, although capable of supporting a green wall does not present the same level of benefits as described

Figure 112. Visualisation of possible arrangement of green facade from the north west


Green façade

a) Structural capacityw It is most likely that the existing steelwork atrium frame of the lift well due to the presence of the substantial steel framing structure. The masonry walls of the southern and northern wing may support a green wall or façade, however the capacity of the masonry walls will need to be confirmed through further structural assessment possibly with intrusive exploratory works.


The existing roof drainage system of the southern wing could easily be configured to direct roof run-off into a water storage that could be located below the portico at the northern side.


Green façade

c) wind effects As the three subject walls form a courtyard wind exposure is not significant.

d) building thermal performance The lift well experiences considerable heat loading during summer. This could be considerably reduce with the inclusion of a green façade. There would be some further benefits to the adjoining sections of the building also.

e) noise N/A

f) visual amenity There is great potential for a green façade to contribute positively to the presentation of the entry to the public. At present the courtyard is of low visual appeal and orientation into the building is confused. The provision of a green façade would significantly enhance the presentation of the building entry. Green walls to the north and south wings would also improve this.

This approach could be part of a large awarenss raising communication message to the public about sustainable development practices and the benefits of green infrastructure.

g) urban food production While the production of food on these walls and façades is possible it may not represent the most viable solution. It would also need to be managed from a public access and increased activity point of view.




k) access for maintenance Maintenance access would need to be provided from either top down roof access, of ground up mobile work platform or scissor lift.


l) heritage As the buildng is on the Victorian Heritage Register, heritage implicatison will need to be addressed.

However due to the recent architectural remodelling fo the lift well, any additional encoberances would not likely incur a renewed heritage compliance requirement.

Any green wall mounted to the southern or northern wings may require consideration of heritage values, however as these already have a considerable amount of sewer and stormwater services running across them, it is doubtful that a green wall will impact any further on the heritgae values of these elevations.

Figure 111. Refer Item 4.11.12



3.8 poSt offIce walK, rIchMond

3.8.1 analySIS

design emphasis

a) aesthetic

b) food

c) air quality

overvIew

The Post Office Walk is situated off the busy Victoria Street asian restaurant precinct in Richmond. The subject wall is the eastern side of a privately owned building. The owners currently lease the wall space to advertisers for display of billboards.

The building appears to be of sound condition, however the upper freize is deteriorating and poses a potential public liability issue with the potential for the cemintitous moulding to delaminate and dislodge.

The City of Yarra has a current street works project that involves a rebuild of the pavement and drainage system. It also includes a proposal for an urban design project that involves LED lighting and art work fixed to the walls of a number of buildings alone the lane.


green wall / facadeThe green wall has been identified as a part of the urban design project. Beyond the benefits of visual amenity and improved air quality (and potenital food production) this green wall has the opportunity to engage with the building owner in rectifying the public liability issue relating to the deteriorating decorative moulding.

Along with integration with the urban design and art treament to the lane, the green wall could also provide a food source for the precinct.


Green Wall


The building structure is comprised of a masonry wall. The wall currently supports a advertising hoarding comprised of a steel frame with graphic panels on timber play. The upper frieze of the wall is comprised of a decorative cementitious moulding which is in poor condition and has delaminated. It appears that the structural integrity of the building wall is sound, however their is a risk that the upper moulding may dislodge which poses a considerable safety hazard. It is recommended that this moulding be removed or repaired.

b) drainage considerations The roof of the building drains by way via gutters collecting to down pipes that outlet onto the pavement surface of the lane.


The wall has an eastern aspect which provide early morning sun, with shade for the remainder of the day. This would lend itself to food production.

d) wind considerations The wall is relatively protected from prevailing winds.

e) Seasonal considerations A food production green wall would require regular re planting. This would need to be part of the commercial consideration for the wall.

f) height of building The existing building is 2 story. The subject wall is approximately 10m high. The existing advertising hoarding is approximately 4m high.

g) access for construction The site has easy access for cranes for construction.

h) access for maintenance Access for maintenance could be from ground level. Easy access could be provided with conventional ladders up to 4m.

Figure 113. Proposed urban art project with area for potential green wall shown green

Figure 114. Potential location of green wall

Figure 115. Existing decorative moulding showing signs of deterioration

Figure 116. Subject wall to the right




Green Wall




Existing use of building is a retail food produce (primarily fresh fruit and vegetables). The private owner is currently leasing the wall for the advertising hoarding. The existing delamination of the upper wall moulding is in need of immediate attention / repair.


The eastern orientation of the wall does not create opportunity for the contribution of a green wall for passive thermal performance improvement.


As the building is has no heritage significance, there is no issues related to heritage.

q) factors associated with noise The bustling nature of Victoria Street does not require noise attenuation as it is part of the character of the area.



Consideration will need to be given to recovery of run-off from green wall for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green wall.


Green Wall


Length of subject wall is approximately 12m which would be ample for a productive food wall.


The existing drainage system could easily be connected to an underground water storage within a re built road pavement (pending coordination with existing under ground services and structural assessment of existing building foundations). Over flow from this tanks could be easily directed to the existing stormwater system.


There is potential to grow plants from the ground level along the wall.


Given to proximity of the subject wall to food produce retail and restaurants, and the Asian (Vietnamese) identity of Victoria Street, opportunity exists for the wall to be a food production green wall. The range of herbs and vegetables that could be grown on the wall could be used for culinary purposes. The proximity to the restaurant opposite could provide immediate access to fresh food for inclusion in soups and other meals (potentially served straight out into the lane). It would be possible to provide a hybrid of continuous ground planting, modular, and cable based planting systems.


3.7.1 analySIS

Figure 118. Wall to restaurant oppositeFigure 117. Subject wall



The wall of the proposed subject building could support a green wall which could be mounted to a steel frame not entirely dissimilar to the existing billboard. The rental income which would be lost by removal of this could be offset by income derived from the potential sale of produce grown on the wall.

In tandem with the proposed urban design project, the green wall has the potential to revitalise Post Office Walk which would further be enhanced if the resturant to the east side of the lane could open itself into the lane where meals could be served directly into the lane, comprised of ingredients harvested right off the green wall.

Figure 119. Visualisation of possible arrangement of green facade from the north east


3.8.2 fIndIngS


Green façade

a) Structural capacity It is most likely that a green wall could be supported from the existing masonry walls, although further structural assessment including intrusive exploratory works is required to confirm. The robustness of the structure should also be checked, particularly that the roof and floor plates are tied to the wall plate. Alternatively, a new steelwork frame could be adopted, with lateral restraint gained from the existing wall.


The current development plans for Post Office Walk include to supply and installation of a number of new grated stormwater pits within the road way. These could be re positioned to accomodate an in-ground water storage tank within the re constructed road way.

The down pipes from the subject bulding could be diverted into this tank, as a speparate system to the road run-off drainage. This could provide a water supply for an irrigation system to the green wall.

c) wind effects As the subject wall is orientated to the north with good protection from westerly and southerly wind, adverse wind effects are neglible.

d) building thermal performance Due to the eastern orientation of the subject wall there is little thermal benefit to be gained from a green wall.

e) noise N/A

f) visual amenity The provision of a green wall would integrate with the proposed urban art projects to provide significant visual amenity benefits.

g) urban food production This green wall has the potential to provide a signifiant food production capacity that if integrated with the adjoinging retail produce and resturant establishments could represent a viable commercial incentive.

h) biodiversity and urban habitat

There may be some potential for the green wall to provide habitat for insects and birds.

Consideration would need to be given to issues related to pest animals if it were to be a commerical food production green wall.

i) building code compliance A building permit would be required for any new opening from the existing resturant onto the lane. This may require fire protection depending on ownership of adjoining land and protection during erection.

j) access for construction The is good access for construction.

k) access for maintenance The is good access for maintenance.

l) heritage As the building is has no heritage significance, there is no issues relted to heritage



3.9 prahran MarKet car parK

3.9.1 analySIS

overvIew

The Prahran Market Car Park is located north of Elizabeth Street and has good linkages to the street, the market and the narrow strip of open space along Barry Street to the north. The 2012 Elizabeth Street Master Plan identified opportunities for both green roofs and green wall / facades.

The Prahran Market Stormwater Reuse and Protection Project captures 60,000L of roof run-off in a 70m long tank in a sub floor tunnel.

The car park although well used, represents opportunities to extend the reach of ecologically sustainable development with the inclusion of a green roof, green walls and facades.


green roofThe consideration of a green roof includes assessment of an area to be given over for a range of activities such as to a commercially viable urban agriculture operation to complement the market activities, a shared community garden, or a garden to supplement the requirements of local residents. A green roof would also provide important urban space for residents of South Yarra where only 7% of land is open space, and projected figures indicate the area will see higher pressures placed upon public land, compared to other areas of Stonnington.

Other propositions include a green roof shade canopy, and green space accessible to the public.

green wall / facadeThe carpark is a ‘stand alone’ building with access from all sides. There is the opportunity to add green walls around the building while still retaining access of light and pedestrian entry points into the car park.

Planing of green walls or façades would be easily accommodated and would provide improved aesthetic and environmental values to the site.

design emphasis

a) food

b) aesthetic

c) public access

d) thermal

e) wSud


Figure 121. Exsiting structure from south east

Figure 122. Exsiting structure from north west




Green roof


The building structure is comprised of insitu concrete parking decks, supported by insitu concrete columns. Car-parks typically have a live load capacity of 2.5kPa, therefore there is at least a spare capacity of 1.0kPa to 1.5kPa. The structure is in-situ reinforced concrete, is in good condition and is around 30 years old. The concrete will have gained high strength, at least 60mPa, therefore the capacity will have increased. Also, experience has shown that the long spans adopted will have been governed by deflection at the design stage, so if we take a pragmatic view on further deflection it is likely that we can ‘push the capacities’ of the building within safe limits.

Accordingly it can be assumed that the load capacity of the top level car park area is in excess 2.5 kPa, and potentially up to 4.0 kPa.

The balustrades are supported by steel framing connected to the car park deck slabs.

b) water proofing The existing concrete car park slabs provide all water proofing.


3.8.1 analySIS

Figure 123. The strucutre is concrete deck supported by concrete columns

Figure 126. Existing DDA access ramp to the south side

Figure 124. The upper deck is visible from residential nearby buildings

Figure 127. There is an opportunity to provide an additinal DDA access ramp to the north

Figure 125. The existing balustrade will afford some wind protection to an otherwise exposed site


Green roof

c) roof slope The roof is of a relatively flat pitch (approximately 1:100 or flatter). This is conducive to a green roof, and will make access and maintenance simple.


The majority of the roof is exposed to full sun.

e) wind considerations The roof top area although exposed to all prevailing winds has the advantage of an existing perimeter balustrade / parapet which afford some level of wind attenuation.

f) Size of useable roof area The area available for a green roof is considerable (approximately 5,300 square metres). A review of the number of car spaces that can be given over to a green roof will need to be made with agreement from stakeholders. These include the retailers, City of Stonnington, and local residents.

The roof car park currently provides car parking for approximately 220 vehicles. The whole of the car park provides a total of 670 car parking spaces. Consideration should also be given to providing a new green roof on top of the existing structure. The new roof could provide a range of functions including additional car parking spaces to offset reduced car parking in Chapel St. The remainder of the new purpose built roof structure would accommodate the green roof and associated uses such as PV panels.

g) height of building The building has two levels of above ground car park and is approximately 6m high.

h) access for construction Access for construction crainage and loading of materials is good.

i) access for maintenance Access for maintenance is good.

j) potential for public access The existing lift and ramps provide good DDA compliant access.

There is potential to provide an second ramp access to the northern side to facilitate ease of access from the residential area and church community, if this was considered desirable.

Figure 128. Down pipes embedded within the columns could be directed to a water storage tank for irrigation re use




Green roof


There is an opportunity for site collected stormwater for irrigation re use to be harvested via the existing stormwater down pipes, provided they can be practically collected into a single storage. Alternatively multiple storage tanks could be considered.


Generally the load bearing capacity of the car park would facilitate provision of an extensive green roof. However due to the potentially high structural load bearing capacity over columns, it is possible that a deeper substrate could be provided in some areas to facilitate the growing of commercially viable food crops, or other gardens requiring similar depth substrate.


The roof is well serviced by potable water, electrical connections, and the provision of reticulated recycled water for irrigation would not be difficult (provided a storage tank is available).

The market currently has 60,000L of rain water storage (UV treated for wash down) consisting of 20 no. 3000L tanks.


The existing use of the building as a public car park makes it conducive to being a publicly accessible green roof. It's proximity to the market makes commercial food production viable.

The opportunity to increase the amount of accessible green open space by providing this green roof is considerable, especially given its proximity to Chapel Street and the densely populated surrounding residential/commercial area.


Due to its open configuration there is little benefit in improving the building's thermal performance.




Determination of the number of car spaces that are able to be given away to the green roof will need to be made.

The option of adding on a ‘purpose built’ third storey could be considered to protect the existing car parking capacity and to allow a new roof construction to suit preferred treatments.

r) factors associated with noise Proximity to adjacent residential properties will require an assessment of the noise impacts of public access especially at night.

Figure 129. The green roof would suppliment the limited amount of existing open space wthin the municipality


3.8.1 analySIS


Green façade


The building structure is comprised of insitu concrete frame and slab. There is some capacity to support a green façade.

b) drainage considerations Capture of run-off from the facade should be considered to recover as much water as possible for irrigation re use.


The south elevations are in semi to full shade which may limit species selection to those that are tolerant of these conditions. The north elevation has good sun access.

d) wind considerations The building is located to the north of the market and is somewhat protected from strong southerly winds. It is exposed to the northern hotter winds. This will influence the plant species selections and irrigation water demand.

e) Seasonal considerations Given the shady exposure, it would be advantageous to consider deciduous species to maximise winter solar access to the building for both light and warmth.





There is potential to utilise a portion of the entire southern and northern elevations. This would improve presentation to the street and screen views of vehicles.


There is an opportunity for site collected stormwater for irrigation re use to be harvested via the existing stormwater down pipes, provided they can be practically collected into a single storage. Alternatively multiple storage tanks could be considered.



green roof

The upper deck of the car park could accommodate a green roof provided that the removal of the required number of car spaces can be negotiated. If this is considered a problematic proposition, then consideration should be given to providing an additional upper roof canopy over the existing top car park deck. This could be configured to support a green roof which would not impact on the numbers of car parking, and provide a significant amount of usable green open space.

The range of programs for the space is open to exploration. There is potential for the garden to provide commercial food production which could be sold at the market. This would provide immediately fresh produce with zero food miles.

Alternatively (or in conjunction with this) the space could become usable public open space and programed to be used for passive recreation, markets, or any range of public entertainment.

green wall / facade

The southern elevation of the car park structure could be easiliy configered as a green wall / facade. This initiative would represent strong visual connection of the car park with Elizabeth Street, and the market itself.

The green wall / facades could take the form of green facades grown on supporting structures, that could comprise of modular green walls, combined with cables supporting climbing plants.


3.9.2 fIndIngS


Green roof

a) Structural capacity The existing structure is likely to be capable of carrying an extensvie green roof plus a limited number of people without structural augmentation.

This is due to the continually strengthening nature of concrete and considering that it will have been designed by governing deflections, it is likely that there is further capacity in the frame beyond the 2.5kPa live load which it has been designed for. It may have a capacity of up to 4.0kPa and should that be exceeded, then further structural strengthening could be adopted in the form of steelwork beams between the downstand reinforced concrete beams.

An alternative would be to construct a new suspended steelwork frame above the deck and load the columns below directly, thereby by-passing the rooftop slab and beam construction. Intrusive exploratory works would be required to assist assessment of existing structural capacity.

As a result it is feasible that a combination of extensive green roof areas, and intensive green roof planters could be accomodated on the upper deck.

b) water proofing The existing car park concrete deck provides sufficient water proofing requirements which would not be compromised by the inclusion of a green roof.

c) drainage The existing car park concrete deck provides sufficient drainage requirements which would not be compromised by the inclusion of a green roof.


Provided the existing down pipes could be tapped into and directed to a water storage tank there is the potential to provide site captured water for irrigation re use. This could either be provided as an above or below ground system depending on cost and spatial constraints.

e) wind effects Due to the presence of a 1.2m high perimeter balustrade and the contribution this will have to protecting the vulnerable edge of any green roof, the impacts of strong winds should not be an issue.

f) building thermal performance Due to the unenclosed nature of the structure, there are no thermal benefits to be had from a green roof located on the upper deck.

If a secondary roof structure was to be provided, this could contribute to the thermal performance of the space below from shading effects.

The provision of a green roof to either scenario will provide improvemens to the urban heat island effect. This will reduce temperatures locally on hot days.

g) noise The provision of a green roof may reduce the impacts from noise generated by cars.


If photo voltaic panels were to be provided on the roof for generation of electrical energy for the building, their performance on hot days could be significantly improved due to the cooling effect of a green roof (up to 25 degrees Celcius). These panels could also be used to provide shade to cars underneath should a third, purpose-built storey be added to the existing structure.




Green roof


N/A

j) visual amenity The provision of a green roof will improve the visual amenity of the area considerably as this space is visible from many locations in the immediate vicinity. This includes the nearby multi story housing commission apartments, as well as the recently constructed residenitial developments to the south, and the Prahran Town Hall.

k) urban food production The potential for a green roof to provide commercially viable source of low food miles fresh produce is significant.

l) biodiversity and urban habitat There is a potential for the green roof to provide a source of flowering plants that would attract bees that could enable the production of honey.

Consideration would need to be given to issues related to pest animals if it were to be a commercial food production green roof.

m) building code compliance As the building is considered publicly accessible then disabled lift access is required. Exit travel distance to nearest single exit of up to 20m, if greater than a second exit or fire engineering. Exit door signage/hardware. Fire hose hydrant (30m hose with 10m hose stream) and hose reel (36m hose) coverage. Waterproofing and stormwater drainage of the roof area requires consideration. Population would be determined by the number of exits (exit width), live load of floor and 2m2 per person. Balustrades around perimeter consider non-climbable, height and construction fixing. Energy efficiency of proposed exterior lighting in terms of control and wattage.

n) access for construction There is good access for construction.

o) access for maintenance There is good access for maintenance.

p) access for the public The provision of a green roof either on the existing car park deck, or a new upper canopy would provide significant green space much needed in the City of Stonnington. This would integrate well with the objectives of the Chapel Street Master Plan.

As the current configuration of the car park roof deck allows public access, the provision of public access to a green roof would be equal from a health and safety point of view.

Consideration would need to be given to the loading capacity of the structure. Refer Item 1.


3.8.2 fIndIngS


Green façade

a) Structural capacity The concrete columns will have some load bearing capacity for a green facade, depending on the degree of canterlevering required in the design. It is likely to support a green facade with lightweight framing with no augmentation of the existing structure.


The car park deck drainage system could easily be configured to direct roof run-off into a water storage. Provided the existing down pipes could be tapped into and directed to a water storage tank there is the potential to provide site captured water for irrigation re use. This could either be provided as an above or below ground system depending on cost and spatial constraints.

c) wind effects The supporting structure of the green façade could be designed to accomodate the wind loads. Plant species selection would need also to consider wind effects in terms of water loss in transpiration, as well as ability to tollerate wind shear.

d) building thermal performance As the subject building elevations are on the southern and northern sides, there would be little contribution to building thermal performance in summer in terms of cooling.

e) noise N/A

f) visual amenity There is great potential for a green façade to contribute positively to the presentation of the building to the street, and make a strong statement about green infrastructure and ESD in the City of Stonnington.

This would integrate well with the objectives of the Chapel Street Master Plan.





k) access for maintenance Maintenance access would need to be provided from either top down roof access, on-ground up mobile work platform or scissor lift.


l) heritage As the building is has no heritage significance, there is no issues related to heritage



3.10 Surrey road parK, prahran

3.10.1 analySIS

design emphasis

a) aesthetic

b) biodiversity

c) acoustic

d) air quality

e) wSud

overvIew

The existing sound wall along the southern edge of the Surrey Road Park is the primary subject of this site. The park is owned by Council and is currently being re developed as a public park with feature landscape. The park also includes raingardens and an irrigation system.

The land upon which the wall has been erected is owned by the City of Stonnington and leased to the body corporate of the adjoining residential development. The wall is an acoustic attentuation barrier to enable planning and building code compliance for the adjacent residential development due to proximity of the railway line to residential apartments.


green wall / facadeAs the new park will have a relatively high level of quality to the finishes and treatments, it is Council’s desire that some sort of treatment be given to the wall in order to improve it’s visual amenity.

Accordingly the subject wall being considered is a green wall or green wall / facade.

Figure 130. Subject wall frmo side with adjacent residentil aprartment building behind

Figure 131. Location plan with subject wall shown green

Figure 132. Subject wall from front Figure 133. Subject wall is concrete supported by a steel frame and in ground posts

Figure 134. The existing site is well serviced by drainage


Green Wall

a) type of structure and load bearing capacity (concrete / steel frame, brick, curtain wall)

The wall is comprised of pre cast concrete panels, supported by steel columns for both gravity and wind. Horizontal rail members provide an arrangement such that the frame spans the existing underground stormwater and sewer pipes.

The existing wall has a significant capacity to accommodate additional loads from a green wall.

b) drainage considerations There is ample opportunity to re cover run-off from the wall and direct this into the proposed rain gardens and planting beds located within the vicinity of the wall.

c) Shading / sunlight availability (aspect) and exposure

The wall has a northern aspect which provides full sun for most of the day. Shading by the adjoining building will need to be a consideration for part of the wall.

d) wind considerations The wall is subject to strong northerly winds.

e) Seasonal considerations

f) access for construction The site has easy access for cranes for construction.

g) access for maintenance Access for maintenance could be from ground level. Easy access could be provided with conventional ladders up to 4m.

Maintenance of wall is the responsibility of the body corporate. An agreement needs to be struck with body corporate in relation to maintenance.

h) Size of useable wall or façade area

Length of subject wall is approximately 26m long and 10m high which if planted, would contribute greatly to the visual amenity of the park.




Green Wall

o) factors associated with town planning, building permits, bca compliance and heritage issues

As the building has no heritage significance, there are no issues related to heritage.

p) factors associated with noise The noise from the train line to the back of the wall will be further attenuated for the provision of vertical greening.

q) fire risk No significant fire issues related to a green façade.

r) Stormwater discharge point of building

Consideration will need to be given to recovery of run-off from green wall for re circulation. Consideration of the water quality issues related to this will be required in terms of nutrient loading on the receiving stormwater system, as well as potential for pathogens harmful to plant growth on the green wall.


Green Wall

i) opportunities for site capture and storage of water for irrigation

Consideration should be given to retaining the existing stormwater harvesting system (if it is not already demolished), providing a new one to service the irrigation requirements for the green wall. This could easily be accommodated within the current design.

Alternative options for irrigation could include collection of water from roofs of the adjoining apartments, subject to permission from Body Corporate / owners.

j) available space for plants to be grown from ground level upwards

There is potential to grow plants from the ground level along the wall.

k) opportunities for more than one type of wall or façade. what type of green wall / facade (continuous/modular?)

Given the proximity of the subject wall to the existing park and adjacent residential development, there is a great opportunity to provide a high value amenity to people in terms of visual amenity, and emphasis of green space.

l) access to utilities (water, electricity)


Conduits have been run to facilitate the installation of electricity supply.

m) existing use/s of building (e.g. commercial, residential)

Existing use of area is residential, with a significant outlook onto the wall. There is an existing ground water decontamination plant which may require consideration in terms of green wall opportunities.

n) opportunity for improvement of building thermal performance

The radiant heat from the wall will be attenuated by the greening of this wall. This will provide a benefit in terms of a reduction of heat loads onto the adjacent residential development.


3.9.1 analySIS

Figure 135. The future park redevelopment includes WSUD raingardens and irrigation

Figure 136. The adjacent residential apartments would benefit from reduced reflected heat loads with the provision of a green facade

Figure 137. A green facade would contribute to noise reduction function of the sound wall




3.10.2 fIndIngSThe acoustic wall at Surrey Road Park currently has a very poor visual amenity. This would be greatly improved with the provision of a green wall. The existing structure could easily accommodate the loads imposed by such a wall. The existing park would need to accommodate the required stormwater harvesting and storage in order that irrigation from mains water supply be avoided.

There is a further opportunity to screen the existing ground water decontamination facility with smaller green wall installations.


Green Wall

a) Structural capacity The existing structure would support additional self-weight loading of 300kg/square metres to sections of the wall. The wind load would be largely unaffected and the stresses imposed from lateral forces (primarily wind) would not change. The new structure should be directly connected to the steelwork frame.


Provided the run-off from the green wall could be recovered, then it is possible that an in-ground water storage tank could service the irrigation requirements.

The source of the run-off for such a tank would need to come from the adjacent residential development.

This system shoud be compatible and integrated with the stormwater management system for Surrey Road Park.

c) wind effects Provided that the structural capacity of the existing wall is designed for the site’s exposure classification for wind impacts, then the green wall can be design to tolerate these loads from a vegetation shear impact point of view.

d) building thermal performance N/A

e) noise The green wall will contribute to the acousitic attenuation properties of the existing concrete wall.

f) visual amenity A green wall will contribute significantly to the visual amenity of the park. This is the single most important benefit, and the planting and support structure should be designed to achieve this objective.

g) urban food production There is potential for the green wall to provide space for growing of communal food, however this should not compromise the visual amenity performance objectives.

h) biodiversity and urban habitat There is a potential for the green roof to provide a source of flowering plants that would attract bees that could enable the production of honey.

Consideration would need to be given to issues related to pest animals if it were to be a commerical food production green roof.

i) building code compliance No issues unless retaining walls over 1 m are proposed, then a building permit is required.

j) access for construction There is good access for construction.

k) access for maintenance There is good access for maintenance.

l) heritage N/A


4. RefeRences

Allison, R. et al. 2005. WSUD Engineering Procedures: Stormwater. CSIRO Publishing.

Dunnett, N. and Kingsbury, N. 2008. Planting Green Roofs and Living Walls. Timber Press.

Hitchmough, J. 1994. Urban Landscape Management. Inkata Press.

Hopkins, G. and Clay, R. 2012. Green Roof Trials Monitoring Report. Government of South Australia and Aspen Development Fund No.1.

Hopkins, G. and Goodwin, C. 2011. Living Architecture - Green Roof and Walls. CSIRO Publishing

Hopkins, G. Goodwin, C. Milutinovic, M. and Andrew, M. 2010. Feasibility Study: Living wall system for multi-storey buildings in the Adelaide climate. Government of South Australia.

Hopkins, G. Goodwin, C. Milutinovic, M. and Andrew, M. 2012. Post-construction monitoring report: Living wall system for multi-storey buildings in the Adelaide climate. Government of South Australia and Aspen Developments.

Lamberttini, A and Leenhardt, J. 2007. Vertical Gardens - Bringing the City to Life. Thames & Hudson Ltd.

Luckett, K. 2009. Green Roof Construction and Maintenance. McGraw-Hill Construction.

Snodgrass E. and McIntyre, L. 2010. The Green Roof Manual - A Professional Guide to Design, Installation, and Maintenance. Timber Press, Inc.

Van Renterghem, T. et al. 2013. The potential of building envelope greening to achieve quietness. Building and Environment, 61, 34–44. DOI:10.1016/j.buildenv.2012.12.001

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