sunlight report cross avenue residential development

SUNLIGHT REPORT

CROSS AVENUE RESIDENTIAL DEVELOPMENT

20841

20841-VCE-ZZ-XX-RP-SU-001 i Cross Avenue Residential Development

DOCUMENT CONTROL

Rev Purpose Issued to Issued by Date Notes

00 Review Project Team VCE 20/06/2021 Draft

01 Review Project Team VCE 01/07/2021 Draft

02 Planning Project Team VCE 07/07/2021 Minor updates

03 Planning Project Team VCE 13/07/2021

04 Planning Project Team VCE 21/07/2021 Additional analysis

05 Planning Project Team VCE 28/07/2021 Minor Updates

CONTENTS

1. Executive Summary: .................................................................................................................. 1

2. Introduction ............................................................................................................................... 2

Conclusions .............................................................................................................................. 4

3. Skylight to the Surrounding Existing Residential Buildings ....................................................... 5

Vertical Sky Component .......................................................................................................... 5

Goleen ..................................................................................................................................... 7

Little Oaks, 1 St. Margaret’s ................................................................................................. 10

2 St. Margaret’s ..................................................................................................................... 13

3 Dunamase, St. Margaret’s .................................................................................................. 15

4. Sunlight to Surrounding Existing Residential Buildings ........................................................... 17

Summary of APSH and WPSH Results. ................................................................................... 18

Existing and Proposed Annual Probable Sunlit Hours (APSH) ............................................... 19

Existing and Proposed Winter Probable Sunlit Hours (WPSH) .............................................. 20

5. Overshadowing ......................................................................................................................... 22

Shadow Diagrams for 21st March ........................................................................................... 23

Shadow Diagrams for 21st June ............................................................................................. 27

Shadow Diagrams for 21st September ................................................................................... 31

Shadow Diagrams for 21st December .................................................................................... 35

6. Sunlight to Amenity Spaces ..................................................................................................... 39

Summary of Results for Amenity Spaces .............................................................................. 39

Amenity Spaces within the Proposed Scheme ...................................................................... 40

Sunlight to Adjacent Residential Amenity Spaces ................................................................ 42

Appendix 1 – Point Cloud Survey Drawing ............................................................................................ 45

20841

20841-VCE-ZZ-XX-RP-SU-001 1 Cross Avenue Residential Development

SUNLIGHT REPORT

CROSS AVENUE RESIDENTIAL DEVELOPMENT

1. Executive Summary:

Varming Consulting Engineers were engaged to provide sunlight analysis for the proposed Cross Avenue

Residential Development. The assessment was guided by the principles set out in BRE 209, ‘Site Layout Planning

for Daylight and Sunlight: A Guide to Good Practice’, Second Edition 2011 and BS 8206-2:2008 “Lighting for

buildings – Part 2: Code of practice for daylighting”.

The purpose of this report is to evaluate the quality and quantity of sunlight to the amenity areas of the scheme

and the impact, if any, to the availability of skylight and sunlight to surrounding residential dwellings and amenity

spaces. The model geometry which is the subject of this report was modelled in IES <Virtual Environmental> and

was based on drawings received from Urban Agency.

For assessment of the daylight to apartments within the development please refer to the Varming daylight report

20841-VCE-ZZ-XX-RP-SU-002.

Figure 1: Overview of site

20841


Shadow maps, contained in section 6, have been produced to inform the design development of the scheme and

to try to maximise the sunlight levels to the development. The methodology and context of the sunlight evaluation

is discussed in section 2.

BRE guidance states that for existing buildings obstruction of sunlight may be an issue if some part of a new

development is situated within 90 degrees due South of a main window wall and suggests evaluating using

Vertical Sky Component (VSC) at the Centre of the lowest window where daylight is required. A comparison of the

existing VSC and predicted situation were carried out for all windows which could be identified and the results in

section 2 show that all 36 windows evaluated will receive adequate skylight as they exceed the minimum advisory

VSC threshold of 27% after construction of the proposed development.

Access to sunlight was evaluated in relation to Annual Probable Sunlit Hours (APSH) which is the total number of

hours in the year that the sun is expected to shine on unobstructed ground while allowing for average monthly

levels of cloud cover for the specific location and is dependent on the latitude and longitude of the location. A

comparison of the APSH for both the existing situation and predicted situation post construction shown in section

4 illustrates that of 47 windows and rooflights evaluated 45 of them or 96% comply with BS8206 recommendations

that the centre of the window in the main living space should receive at least 25% of the Annual Probable Sunlit

Hours, at least 5% of the APSH from 21st September to 21st March (Winter Probable Sunlit Hours), and where

and if there is a reduction in light due to a new development the available sunlight hours should be greater than

80% of their former value.

The assessment was guided by the principles set out in BRE 209, ‘Site Layout Planning for Daylight and Sunlight:

A Guide to Good Practice’, Second Edition 2011. This report quantifies the predicted sunlight to amenity spaces

within the proposed development including roof terraces, along with adjacent amenity spaces of sensitive

receptors. BRE Guidelines recommend that at least 50% of an amenity area should receive a minimum 2 hours

sunlight on March 21st. Detailed results for each block are in section 7.1 while results for sensitive receptors are

contained in section 7.2

The results of the analysis show that all areas evaluated are in compliance with BRE guidelines and has been

designed in compliance with these parameters.

2. Introduction

BRE 209, ‘Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice’, Second Edition 2011 was

used as the guidance for this evaluation. The BRE guidance advises on planning developments for good access

to daylight and sunlight, and is widely used by local authorities during the planning permission application process

to help determine the impacts of new developments including;

• Provision of natural light to new properties

• Potential losses to existing ones

• Overshadowing

The Cross Avenue Residential Development which is the subject of this report was modelled in IES <Virtual

Environmental> and the geometry was based on data received from Urban Agency..

Overshadowing

Shadow maps have been produced to inform the design development of the scheme and to try to maximise the

sunlight levels to amenity spaces. The methodology and context of the sunlight evaluation is discussed in section

2.

Overshadowing was visualized and analysed using Suncast which is used to investigate external obstruction and

self-shading of a building by generating shading and solar insolation images from any sun position defined by

date, time, orientation, site latitude and longitude. For this evaluation the following coordinates were used;

The following coordinates were uses for the evaluation;

Latitude: 53°18'07.3"n

Longitude: 6°11'28.4"w

BRE 209 uses the equinox, March 21st for evaluation of sunlight, skylight and daylight. The statistics of Met

Eireann show that during December, Dublin receives a mean daily duration of 1.7 hours of sunlight (only 22% of

potential sunlight hours) and during June, receives a mean daily duration of 6.4 hours of sunlight (38% of

potential sunlight hours). The summer solstice is the best case scenario with minimal shadows due to the height of

the sun, and winter solstice is the worst case, when it is common for large areas of the ground to be in shadow

due to the suns low angle and shorter days. Therefore for consistency and in line with BRE guidance we have

also used March 21st in overshadowing analysis to represent the average condition across the year. For

completeness we have also included diagrams for June 21st, 21st September and 21st December.

Regarding the assessment of nearby sensitive receptors, there are houses along the western edge on St.

Margaret’s which have been considered. These were evaluated further in terms of Vertical Sky Component,

Annual Probable Sunlit Hours and Sunlight to the amenity spaces. Areas to the north, south and east are too far

away and not considered sensitive in terms of BRE requirements.

Shadow maps in themselves do not provide quantitative metrics however they are useful to visualize any

overshadowing and to investigate whether buildings shade existing or proposed open spaces and sensitive

receptors. We have provided shadow maps showing the areas in shade at different times of day on March 21st as

shown in section 6 to determine areas requiring further investigation.

20841


Skylight to Surrounding Existing Residential Dwell ings;

BRE guidance states that for existing buildings obstruction of sunlight may be an issue if some part of a new

development is situated within 90 degrees due South of a main window wall and suggests evaluating using

Vertical Sky Component (VSC) at the Centre of the lowest window where daylight is required.

It should be noted that these dwellings have mature trees and vegetation shielding them from the proposed

development site and as such a number of methods were required to determine the dimensions and location of

windows. This required a combination of point cloud survey data, reference to planning documents, Google Earth

and photographic survey. The presence of this vegetation will eliminate any potential impact due to their

overshadowing effect however, to determine the worst case scenario for the purpose of this evaluation we have

not included the trees.

A comparison of the existing VSC and predicted situation were carried out for all 36 windows which could be

identified and the results in section 2 show that all windows evaluated will receive adequate skylight as they

exceed the minimum advisory VSC threshold of 27% after construction of the proposed development. As VSC is a

measure of the amount of skylight falling on a vertical window and all the windows evaluated exceed the minimum

required levels it is not appropriate to evaluate the rooflights for VSC

Sunlight to Surrounding Existing Residential Dwell ings

Access to sunlight is evaluated in relation to Annual Probable Sunlit Hours (APSH) which is the total number of

hours in the year that the sun is expected to shine on unobstructed ground while allowing for average monthly

levels of cloud cover for the specific location and is dependent on the latitude and longitude of the location. Winter

Probable Sunlit Hours (WPSH) is the APSH from 21st September to 21st March. BS 8206-2 states that for

existing buildings obstruction of sunlight may be an issue if some part of a new development is situated within 90

degrees due South of a main window wall.

A comparison of the APSH for both the existing situation and predicted situation post construction shown in

section 4 illustrates that 47 windows and rooflights evaluated 45 of them or 96% comply with BS8206

recommendations that the centre of the window in the main living space should receive at least 25% of the Annual

Probable Sunlit Hours, at least 5% of the APSH from 21st September to 21st March (WPSH), and where the

minimum threaholds are not met and there is a reduction in light due to a new development the available sunlight

hours should be greater than 80% of their former value. The exceptions are windows 7 and 8 in 2 St. Margaret’s

which although passing the annual criteria do not achieve the 5% winter criteria. Window 8 fails the WPSH criteria

in its present form due to overshadowing from the extension to the rear of the property, which also impact window

7.

Sunlight to Amenity Spaces

The availability of sunlight in public spaces, including those between buildings, plays an important role in the

overall appearance and ambience of a development along with making outdoor activities more pleasant. Amenity

areas which should be checked for access to sunlight are defined in the BRE guide as follows;

• Gardens, usually the main or back garden of a house and allotments

• Parks and playing fields

• Children’s playgrounds

• Outdoor swimming pools and paddling pools

• Sitting-out areas, such as those between non-domestic buildings and public squares

• Focal points for views, such as a group monument or fountains.

We carried out an evaluation of all amenity within the proposed development and the adjacent gardens of

sensitive receptors. The BRE guidance is the same for both public and private amenity areas in that at least 50%

of the area should receive at least 2 hours of sunlight on March 21st.

Sunlight exposure was evaluated by generating a 1m² grid across each amenity area. Solar exposure results were

calculated for each point of the grid, utilizing hourly solar shading data specific to the location, to determine the

availability of sunlight in hours and percentage of available hours for the specified period.

This report quantifies the predicted sunlight to amenity spaces within the proposed development site such as roof

terraces along with gardens of surrounding existing residential dwellings. Sunlight exposure was evaluated by

generating a 1m2 grid across each amenity area. Solar exposure results were calculated for each point of the grid,

utilizing hourly solar shading data specific to the location, to determine the availability of sunlight in hours and

percentage of available hours for the specified period. The results in section 7 show that all amenity spaces

evaluated exceed BRE guidelines that at least 50% of an amenity area should receive a minimum 2 hours sunlight

on March 21st. The analysis is based on guidance in the following documents;

BRE guide ‘Site Layout Planning for Daylight and Sunlight’ (2nd edit ion)

The BRE guide, contains guidance on how to design developments, whilst minimising the impacts on existing

buildings from overshadowing and reduced levels of daylight and sunlight. In addition, the BRE report provides

advice on how to design buildings to ensure that good practice levels of daylight and sunlight are provided.

As well as advice, the report contains a methodology to assess levels of daylight, sunlight and overshadowing,

and specifies criteria to determine the potential impacts of new development on surrounding buildings, and also to

determine whether new developments are well lit internally.

The BRE Report states that its own numerical guidelines ‘should be interpreted flexibly since natural lighting is

only one of many factors in site layout design. In special circumstances, the developer or planning authority may

wish to use different target values.

20841


Urban Development and Building Heights: Guidelines for Planning Authorit ies

The ‘Urban Development and Building Heights Guidelines for Planning Authorities’ published by the Department

of Housing, Planning and Local Government identify that as reflected in the National Planning Framework:

“that there is significant scope to accommodate anticipated population growth and development needs, whether

for housing, employment or other purposes, by building up and consolidating the development of our existing

urban areas’ and that ‘securing compact and sustainable urban growth means focusing on reusing previously

developed ‘brownfield’ land, building up infill sites (which may not have been built on before) and either reusing or

redeveloping existing sites and buildings, in well-serviced urban locations, particularly those served by good public

transport and supporting services, including employment opportunities”.

The Guidelines reference NPO 13 (from the NPF) which states that

“In urban areas, planning and related standards, including in particular building height and car parking will be

based on performance criteria that seek to achieve well-designed high-quality outcomes in order to achieve

targeted growth. These standards will be subject to a range of tolerance that enables alternative solutions to be

proposed to achieve stated outcomes, provided public safety is not compromised and the environment is suitably

protected’.

One of the key performance indicators identified in these statutory guidelines relates to daylight and sunlight

standards. Section 3.0 of the Urban Building Height Guidelines provides guidance for Planning Authorities and An

Bord Pleanala in considering development proposals for buildings taller than prevailing building heights in pursuit

of the Guidelines. In respect of the site/building scale the guidelines require consideration of:

• The form, massing and height of proposed developments should be carefully modulated so as to

maximise access to natural daylight, ventilation and views and minimise overshadowing and loss of light.

• Appropriate and reasonable regard should be taken of quantitative performance approaches to daylight

provision outlined in guides like the Building Research Establishment’s ‘Site Layout Planning for Daylight

and Sunlight (2nd Edition or BS 8206-2:2008 – ‘Lighting for Buildings- Part Local Planning Policy and

Guidelines

The proposed scheme has been designed recognizing the overall intent of the guidelines and significant volumes

of the buildings have been omitted to offer a ‘well designed, high quality scheme’. As stated in the guidance

documents above, daylight and sunlight are not the only criteria which must be considered and a workable

compromise has been proposed.

Conclusions

In carrying out this study we have adhered to quantitative performance approaches to sunlight provision set out in

BRE 209, ‘Site Layout Planning for Daylight and Sunlight: A Guide to Good Practice’, Second Edition 2011 and

have shown that all amenity spaces meet the BRE recommended criteria. In addition having evaluated the

sensitive receptors it was shown that all windows which could be identified achieve the required levels of sunlight

and skylight.

All 36 windows (excluding rooflights and skylights) evaluated for Vertical Sky Component comply guidance that

the VSC should be above 27% post construction illustrating that enough skylight should still reach the window of

existing sensitive receptors.

Of the 47 windows and roof lights evaluated 45 of or 96% have a predicted APSH is in excess of the BS 8206

minimum advisory threshold of 25% and the WPSH is in excess of the corresponding threshold of 5%. The

exceptions are windows 7 and 8 in 2 St. Margaret’s which although passing the annual criteria do not achieve the

5% winter criteria. Window 8 fails the WPSH criteria in its present form due to overshadowing from the extension

to the rear of the property, which also impacts window 7, irrespective of the current proposal. Please refer to figure

19.

However both these windows exceed the criteria for VSC and according to the planning application drawings the

rooms associated with windows 7 and 8 are a dinette and kitchen respectively. BRE guide states at paragraph

3.1.2 that sunlight is viewed as less important in bedrooms (and kitchens), where people prefer it in the morning

rather than the afternoon. In addition the extent of vegetation, trees and boundary wall in the vicinity of these

windows will impact the available sunlight.

The BRE guidance in itself aims to help rather than constrain the designer. Although it gives numerical guidelines,

it suggests these should be interpreted flexibly since natural lighting is only one of many factors which influence

site layout and fenestration design.

This is in line with the National Planning Framework with regard to urban planning;

“In urban areas, planning and related standards, including in particular building height and car parking will

be based on performance criteria that seek to achieve well-designed high-quality outcomes in order to

achieve targeted growth. These standards will be subject to a range of tolerance that enables alternative

solutions to be proposed to achieve stated outcomes, provided public safety is not compromised and the

environment is suitably protected.”

The current design has carefully considered maximizing solar access to the amenity spaces within the

development and minimising any potential impact on adjacent residential dwellings.

The project team took into consideration the provisions of the “Urban Development and Building Heights –

Guidelines for Planning Authorities” published by the Department of Environment Housing and Local Government

in 2018, which advises “appropriate and reasonable regard” to the relevant guidelines rather than stringent

adherence, and is relevant to the scale of the Phase 1 site;

“The form, massing and height of proposed developments should be carefully modulated so as to

maximise access to natural daylight, ventilation and views and minimise overshadowing and loss of light”

The height of Block A on the west side of the development have been reduced to minimise any potential

overshadowing or loss of light to sensitive receptors. Additionally fully landscaped terraces, accessible to all

residents of the development, have been provided in Blocks B and C to ensure access to sunlit external areas.

20841


3. Skylight to the Surrounding Existing Residential Buildings

Vertical Sky Component

Figure 2: Adjacent residential dwellings

To test the robustness of the proposed design adjacent dwellings were evaluated for VSC. The Vertical Sky

Component (VSC) is defined as “The ratio of that part of illuminance, at a point on a given vertical plane that is

received directly from a CIE Standard Overcast Sky, to illuminance on a horizontal plane due to an unobstructed

hemisphere of this sky”.

It should be noted that these dwellings have mature trees shielding them from the proposed development site and

as such a number of methods were required to determine the dimensions and location of windows. This required a

combination of point cloud survey data, reference to planning documents, and photographic survey. The presence

of this vegetation will eliminate any potential impact due to their overshadowing effect however, to determine the

worst case scenario for the purpose of this evaluation we have not included the trees.

Point cloud survey data

The locations and dimensions of twelve windows were determined in the survey. Due to the previously mentioned

vegetation other windows were obscured. The output of the survey is represented in the following drawing

provided by Murphys Surveys;

Drawing Name Fie Type Description Received

MGL39673_T_ITM_Rev0-00 DWG Topographical Survey 08/03/2021

Planning documents

Reference was made to drawings submitted to Dun laoghaire Rathdown Council Planning Department in support

of the following planning applications.

Planning Ref Location Description Dated

D14B/0031 Little Oaks, 1 St.

Margarets, Cross

Avenue, Blackrock

Permissions for alterations to

external elevations including

changes to the windows and

doors to the front, sides and

rear of the existing house.

February 2014

D01B/0348 No.2 St. Margarets,

Cross Avenue,

Blackrock

Proposed alterations April 2001

D03B/0215 3 Dunamase, St.

Margarets, Cross

Avenue,

Booterstown, Co.

Dublin

Proposed alterations and

extension

March 2003

The quality and quantity of daylight in an existing residential building can be impacted by obstructions caused by

new developments. One indicator suggested by BRE in the guidance document “Site Layout Planning for Daylight

and Sunlight” to measure the impact caused is to evaluate the Vertical Sky Component (VSC) at the centre of the

lowest window where daylight is required.

If the VSC can be maintained above 27%, then enough skylight should still reach the window of an existing

building. If the resultant VSC is both less than 27% and reduced by more than 20% of its former value after the

construction of the proposed development, occupants of the building will notice a reduction in skylight.

Goleen

1 St. Margaret’s

2 St. Margaret’s

3 St. Margaret’s

20841


The results in Table 1 show that all adjacent residential dwellings are predicted to have a VSC in excess of the

minimum advisory 27% and the reduction in VSC caused by the proposed new development is negligible and will

have no perceived impact. As VSC is a measure of the amount of skylight falling on a vertical window and all the

windows evaluated exceed the minimum required levels it is not appropriate to evaluate the rooflights for VSC.

Figure 3: Model image

Figure 4: Model Image

Dwelling VSC Ratio Proposed/ Existing

Compliance with BRE Guidelines (Yes/No)

Undeveloped Site

Proposed Scheme

VSC>27% VSC >80% of previous

Goleen

Window 1 38.91 32.92 84.61% Yes Yes

Window 2 38.24 33.00 86.30% Yes Yes

Window 3 38.32 33.06 86.27% Yes Yes

Window 4 38.35 38.25 99.74% Yes Yes

Window 5 36.12 30.68 84.94% Yes Yes

Window 6 36.66 30.88 84.23% Yes Yes

Window 7 36.23 35.69 98.51% Yes Yes

Window 8 37.60 37.22 98.99% Yes Yes

Window 9 38.62 37.77 97.80% Yes Yes

Window 10 34.65 34.25 98.85% Yes Yes

Little Oaks, 1 St. Margaret

Window 1 36.98 33.82 91.45% Yes Yes

Window 2 37.63 35.31 93.83% Yes Yes

Window 3 38.37 35.42 92.31% Yes Yes

Window 4 39.25 34.74 88.51% Yes Yes

Window 5 39.24 35.01 89.22% Yes Yes

Window 6 39.25 35.42 90.24% Yes Yes

Window 7 35.98 35.08 97.50% Yes Yes

Window 8 38.09 37.67 98.90% Yes Yes

Window 9 37.77 37.13 98.31% Yes Yes

Window 10 31.89 30.28 94.95% Yes Yes

Window 11 32.02 30.05 93.85% Yes Yes

Table 1: Vertical Sky Component

20841


Dwelling VSC Ratio Proposed/ Existing

Compliance with BRE Guidelines (Yes/No)

Undeveloped Site

Proposed Scheme

VSC>27% VSC >80% of previous

2 St. Margaret’s

Window 1 33.06 32.35 97.85% Yes Yes

Window 2 32.98 31.72 96.18% Yes Yes

Window 3 36.09 33.79 93.63% Yes Yes

Window 4 35.68 33.80 94.73% Yes Yes

Window 5 36.59 33.97 92.84% Yes Yes

Window 6 39.06 36.1 92.42% Yes Yes

Window 7 30.46 28.76 94.42% Yes Yes

Window 8 30.85 30.03 97.34% Yes Yes

3 Dunamase, St. Margaret’s

Window 1 39.62 39.14 98.79% Yes Yes

Window 2 39.59 39.02 98.56% Yes Yes

Window 3 39.47 39.10 99.06% Yes Yes

Window 4 39.85 38.45 96.49% Yes Yes

Window 5 38.80 38.45 99.10% Yes Yes

Window 6 38.28 37.47 97.88% Yes Yes

Window 7 37.51 37.05 98.77% Yes Yes

Table 1a: Vertical Sky Component

Goleen

Reference Data

There were no planning drawings available for Goleen so identification of windows was based on point cloud

survey data, Google Earth and photographic survey.

Figure 5: Google Earth image

20841



Results for Vertical Sky Component (VSC)

Figure 7: Windows evaluated

Dwelling VSC Ratio

Proposed/Existing

Compliance with BRE

Guidelines (Yes/No)

Undeveloped

Site

Proposed

Scheme

VSC>27% VSC >80%

of previous

Goleen

Window 1 38.91 32.92 84.61% Yes Yes

Window 2 38.24 33.00 86.30% Yes Yes

Window 3 38.32 33.06 86.27% Yes Yes

Window 4 38.35 38.25 99.74% Yes Yes

Window 5 36.12 30.68 84.94% Yes Yes

Window 6 36.66 30.88 84.23% Yes Yes

Window 7 36.23 35.69 98.51% Yes Yes

Window 8 37.60 37.22 98.99% Yes Yes

Window 9 38.62 37.77 97.80% Yes Yes

Window 10 34.65 34.25 98.85% Yes Yes

Table 2: Vertical Sky Component

20841


Figure 9: Proposed VSC

20841


Litt le Oaks, 1 St. Margaret’s



Reference Data

Reference was made to the following drawings submitted to Dun laoghaire Rathdown County Council Planning

Department in support of planning application D14B/0031;

Drawing

Number

Description Prepared By Date

13-MRG-11 Proposed ground and first floor plans Dorman Architects January 2014

13-MRG-12 Proposed side elevations Dorman Architects January 2014

13-MRG-13 Proposed front and rear elevations and section Dorman Architects January 2014

Table 3: Reference drawings

Figure 12: Reference drawing; 13-MRG-13, Proposed front and rear elevations and section

20841


Results for Vertical Sky Component (VSC)



Dwelling VSC Ratio

Proposed/Existing

Compliance with BRE

Guidelines (Yes/No)

Undeveloped

Site

Proposed

Scheme

VSC>27% VSC >80%

of previous

Little Oaks, 1 St.

Margaret’s

Window 1 36.98 33.82 91.45% Yes Yes

Window 2 37.63 35.31 93.83% Yes Yes

Window 3 38.37 35.42 92.31% Yes Yes

Window 4 39.25 34.74 88.51% Yes Yes

Window 5 39.24 35.01 89.22% Yes Yes

Window 6 39.25 35.42 90.24% Yes Yes

Window 7 35.98 35.08 97.50% Yes Yes

Window 8 38.09 37.67 98.90% Yes Yes

Window 9 37.77 37.13 98.31% Yes Yes

Window 10 31.89 30.28 94.95% Yes Yes

Window 11* 32.02 30.05 93.85% Yes Yes

Table 4: VSC Results

Note: Window 11 represents the average VSC of the 10 glazed units modelled for the conservatory

20841


Figure 15: Existing VSC


20841


2 St. Margaret’s


Figure 18: Dwelling evaluated

Reference Data


Department in support of a planning application D01B/0348 submitted in May 2001.

Drawing

Number

Description Prepared By Issued for Planning

1001-P03 Site Plan Christopher Ryan Architect May 2001

1001-P04 Proposed first floor

and attic plan

Christopher Ryan Architect May 2001

1001-P05 Proposed sections Christopher Ryan Architect May 2001

1001-P06 Elevations Christopher Ryan Architect May 2001


Figure 18a: Reference drawing ,

20841



Dwelling VSC Ratio

Proposed/Existing

Compliance with BRE

Guidelines (Yes/No)

Undeveloped

Site

Proposed

Scheme

VSC>27% VSC >80%

of previous

2 St. Margaret’s

Window 1 33.06 32.35 97.85% Yes Yes

Window 2 32.98 31.72 96.18% Yes Yes

Window 3 36.09 33.79 93.63% Yes Yes

Window 4 35.68 33.80 94.73% Yes Yes

Window 5 36.59 33.97 92.84% Yes Yes

Window 6 39.06 36.1 92.42% Yes Yes

Window 7 30.46 28.76 94.42% Yes Yes

Window 8 30.85 30.03 97.34% Yes Yes

Table 6: VSC results



20841




Figure 23: Model image

Reference Data


Department in support of planning application D03B/0215 submitted March 2003..

Drawing

Number

Description Prepared By Issued for Planning

- Proposed floor

plans

Brian O’Donohue Architects March 2003

- Proposed elevations Brian O’Donohue Architects March 2003


Figure 23a: Reference drawing

20841



Dwelling VSC Ratio

Proposed/Existing

Compliance with BRE

Guidelines (Yes/No)

Undeveloped

Site

Proposed

Scheme

VSC>27% VSC >80%

of previous

3 Dunamase, St.

Margaret’s

Window 1 39.62 39.14 98.79% Yes Yes

Window 2 39.59 39.02 98.56% Yes Yes

Window 3 39.47 39.10 99.06% Yes Yes

Window 4 39.85 38.45 96.49% Yes Yes

Window 5 38.80 38.45 99.10% Yes Yes

Window 6 38.28 37.47 97.88% Yes Yes

Window 7 37.51 37.05 98.77% Yes Yes

Table 8: VSC results



20841


4. Sunlight to Surrounding Existing Residential Buildings

Access to sunlight is evaluated in relation to Annual Probable Sunlit Hours (APSH). Annual Probable Sunlit Hours

(APSH) is the total number of hours in the year that the sun is expected to shine on unobstructed ground while

allowing for average monthly levels of cloud cover for the specific location and is dependent on the latitude and

longitude of the location. BS 8206-2 states that for existing buildings obstruction of sunlight may be an issue if

some part of a new development is situated within 90o due South of a main window wall. The recommendation is

that the centre of the window in the main living space;

• Should receive at least 25% of the Annual Probable Sunlit Hours.

• Should receive at least 5% of the WPSH from 21st September to 21st March.

• The available sunlight hours should be greater than 80% of their former value.

If following the new development the existing room could receive more than 25% of probable sunlight hours

including at least 5% of probable sunlight hours in the winter months, between 21st September and 21st March,

then the room would still receive enough sunlight.

Any reduction in sunlight access below this level should be kept to a minimum. If the probable sunlight hours were

both less than this and less than 0.8 times their former value, either over the whole year or just in the winter

months (21 September to 21 March) then the occupants of the existing building would notice the loss of sunlight.

The following results illustrate that of the 47 windows and rooflights evaluated 45 of them or 96% have a predicted

APSH is in excess of the BS 8206 minimum advisory threshold of 25% and the WPSH is in excess of the

corresponding threshold of 5%. The exceptions are windows 7 and 8 in 2 St. Margaret’s which although passing

the annual criteria do not achieve the 5% winter criteria. Window 8 fails the WPSH criteria in its present form due

to overshadowing from the extension to the rear of the property, which also impact window 7.

According to the planning application drawings the rooms associated with windows 7 and 8 are a dinette and

kitchen respectively (refer to figure 26a). It is noted that both of these rooms have a second window serving them

which face east, and that these windows are not the single access to light for these rooms in the winter months. It

is also noted that they have excellent light on average throughout the year.

BRE guide states at paragraph 3.1.2 that sunlight is viewed as less important in bedrooms (and kitchens), where

people prefer it in the morning rather than the afternoon. In addition the extent of vegetation, trees and boundary

wall in the vicinity of these windows will impact the available sunlight.

For completeness we have included the % reduction in light as a result of the proposed development, however it

is important to note that only if the minimum thresholds are not achieved does the percentage reduction in light

become relevant. In this case the threshold of 25% is exceeded so all windows evaluated receive adequate

sunlight throughout the year.

Figure 26a: Drawing from planning application D01B/0348 submitted in May 2001.

20841


Summary of APSH and WPSH Results.

Dwelling APSH (%) WPSH (%) Complies with BS8206

Goleen

Window 1 46.1 17.49 Yes

Window 2 46.43 16.67 Yes

Window 3 47.01 16.67 Yes

Window 4 46.63 16.87 Yes

Window 5 39.58 14.62 Yes

Window 6 40.49 14.97 Yes

Window 7 60.03 27.11 Yes

Window 8 64.37 29.58 Yes

Window 9 66.75 30.78 Yes

Window 10 56.05 27.66 Yes

Little Oaks, 1 St. Margaret’s

Window 1 40.69 15.01 Yes

Window 2 43.76 15.94 Yes

Window 3 43.76 15.94 Yes

Window 4 44.45 13.89 Yes

Window 5 46.55 15.85 Yes

Window 6 48.14 16.89 Yes

Window 7 68.91 27.02 Yes

Window 8 76.15 33.1 Yes

Window 9 76.14 33.08 Yes

Window 10 51.28 19.69 Yes

Window 11 52.46 19.48 Yes

Rooflight 1 49.65 10.38 Yes








Table 9 Sunlight results for APSH and WPSH

Dwelling APSH (%) WPSH (%) Complies with BS8206

2 St. Margaret’s

Window 1 43.23 16.83 Yes

Window 2 31.72 6.81 Yes

Window 3 42.33 16.53 Yes

Window 4 41.9 16.1 Yes

Window 5 39.91 14.11 Yes

Window 6 47.13 15.91 Yes

Window 7 25.88 3.46 No

Window 8 29.03 2.74 No





Window 1 37.5 11.11 Yes

Window 2 37.5 11.11 Yes

Window 3 37.5 11.11 Yes

Window 4 36.52 10.61 Yes

Window 5 37.16 10.99 Yes

Window 6 33.26 9.32 Yes

Window 7 32.47 8.13 Yes

Table 9a: Sunlight results for APSH and WPSH

Windows 7 and 8 at St. Margaret’s although passing the APSH threshold of 25% do not achieve the 5% winter

criteria. Window 8 fails the WPSH criteria in its present form due to overshadowing from the extension to the rear

of the property, which also impacts window 7, irrespective of the current proposal.

It is noted that both of these rooms have a second window serving them which face east, and that these windows

are not the single access to light for these rooms in the winter months. it is also noted that they have excellent

light on average throughout the year receiving 29.23% and 31.09% APSH respectively.

20841


Exist ing and Proposed Annual Probable Sunlit Hours (APSH)

Dwelling Existing APSH (%)

Proposed APSH (%)

Ratio Complies with BS8206

Goleen

Window 1 59.01 46.1 78.12% Yes

Window 2 58.96 46.43 78.75% Yes

Window 3 58.93 47.01 79.77% Yes

Window 4 58.98 46.63 79.06% Yes

Window 5 58.33 39.58 67.86% Yes

Window 6 58.33 40.49 69.42% Yes

Window 7 63.53 60.03 94.49% Yes

Window 8 68.01 64.37 94.65% Yes

Window 9 70.54 66.75 94.63% Yes

Window 10 60.2 56.05 93.11% Yes


Window 1 46.25 40.69 87.98% Yes

Window 2 48.92 43.76 89.45% Yes

Window 3 48.92 43.76 89.45% Yes

Window 4 53.48 44.45 83.12% Yes

Window 5 54.62 46.55 85.23% Yes

Window 6 55.78 48.14 86.30% Yes

Window 7 68.93 68.91 99.97% Yes

Window 8 80.56 76.15 94.53% Yes

Window 9 79.93 76.14 95.26% Yes

Window 10 58.92 51.28 87.03% Yes

Window 11 57.75 52.46 90.84% Yes

Rooflight 1 57.25 49.65 86.72% Yes

Rooflight 2 63.17 56.12 88.84% Yes

Rooflight 3 68.43 54.92 80.26% Yes

Rooflight 4 74.73 63.59 85.09% Yes

Rooflight 5 78.47 73.61 93.81% Yes

Rooflight 6 78.47 73.61 93.81% Yes

Rooflight 7 78.47 73.61 93.81% Yes

Rooflight 8 78.47 73.63 93.83% Yes

Table 10: Annual Probable Sunlit Hours

Dwelling Existing APSH (%)

Proposed APSH (%)


2 St. Margaret’s

Window 1 44.88 43.23 96.32% Yes

Window 2 32.85 31.72 96.56% Yes

Window 3 45.92 42.33 92.18% Yes

Window 4 45.89 41.9 91.31% Yes

Window 5 44.56 39.91 89.56% Yes

Window 6 53.84 47.13 87.54% Yes

Window 7 29.23 25.88 88.54% Yes

Window 8 31.09 29.03 93.37% Yes

Rooflight 1 74.77 70.55 94.36% Yes

Rooflight 2 68.4 63.54 92.89% Yes

Rooflight 3 72.13 67.27 93.26% Yes


Window 1 39.58 37.5 94.74% Yes

Window 2 39.58 37.5 94.74% Yes

Window 3 39.58 37.5 94.74% Yes

Window 4 39.11 36.52 93.38% Yes

Window 5 39.36 37.16 94.41% Yes

Window 6 37.14 33.26 89.55% Yes

Window 7 34.79 32.47 93.33% Yes

Table 10a Annual Probable Sunlit Hours

20841


Exist ing and Proposed Winter Probable Sunlit Hours (WPSH)

Dwelling Existing WPSH (%)

Proposed WPSH (%)


Goleen

Window 1 22.89 16.67 72.83% Yes

Window 2 21.99 16.67 75.81% Yes

Window 3 21.09 16.87 79.99% Yes

Window 4 18.41 14.62 79.41% Yes

Window 5 18.25 14.97 82.03% Yes

Window 6 30.61 27.11 88.57% Yes

Window 7 33.22 29.58 89.04% Yes

Window 8 34.56 30.78 89.06% Yes

Window 9 31.3 27.66 88.37% Yes

Window 10 22.89 16.67 72.83% Yes


Window 1 20.56 15.01 73.01% Yes

Window 2 21.11 15.94 75.51% Yes

Window 3 21.11 15.94 75.51% Yes

Window 4 22.22 13.89 62.51% Yes

Window 5 23.47 15.85 67.53% Yes

Window 6 24.53 16.89 68.85% Yes

Window 7 27.05 27.02 99.89% Yes

Window 8 37.5 33.1 88.27% Yes

Window 9 36.87 33.08 89.72% Yes

Window 10 27.33 19.69 72.05% Yes

Window 11 24.56 19.48 79.32% Yes

Rooflight 1 13.46 10.38 77.12% Yes

Rooflight 2 13.81 11.04 79.94% Yes

Rooflight 3 30.67 19.82 64.62% Yes

Rooflight 4 31.4 22.68 72.23% Yes

Rooflight 5 30.56 27.08 88.61% Yes

Rooflight 6 30.56 27.08 88.61% Yes

Rooflight 7 30.56 27.08 88.61% Yes

Rooflight 8 30.56 27.08 88.61% Yes

Table 11: Results for Winter Probeble Sunlight Hours

Dwelling Existing

WPSH (%)

Proposed

WPSH (%)


2 St. Margaret’s

Window 1 18.47 16.83 91.12% Yes

Window 2 7.94 6.81 85.77% Yes

Window 3 20.11 16.53 82.20% Yes

Window 4 20.09 16.1 80.14% Yes

Window 5 18.76 14.11 75.21% Yes

Window 6 22.62 15.91 70.34% Yes

Window 7 6.81 3.46 50.81% No

Window 8 4.8 2.74 57.08% No

Rooflight 1 26.85 26.85 89.50% Yes

Rooflight 2 21.61 21.61 83.94% Yes

Rooflight 3 24.26 24.26 85.70% Yes


Window 1 13.19 11.11 84.23% Yes

Window 2 13.19 11.11 84.23% Yes

Window 3 13.19 11.11 84.23% Yes

Window 4 13.19 10.61 80.44% Yes

Window 5 13.19 10.99 83.32% Yes

Window 6 13.19 9.32 70.66% Yes

Window 7 10.45 8.13 77.80% Yes

Table 11a: Results for Winter Probeble Sunlight Hours

Windows 7 and 8 at St. Margaret’s although passing the APSH threshold of 25% do not achieve the 5% winter

criteria. Window 8 fails the WPSH criteria in its present form due to overshadowing from the extension to the rear

of the property, which also impacts window 7, irrespective of the current proposal.

It is noted that both of these rooms have a second window serving them which face east, and that these windows

are not the single access to light for these rooms in the winter months. it is also noted that they have excellent

light on average throughout the year receiving 29.23% and 31.09% APSH respectively.

20841


Figure 27: Windows failing Winter Probable Sunlit Hours criteria

Figure 28: Location of windows from Google Earth

20841


5. Overshadowing

The shadow maps presented here were used to visualize any overshadowing of buildings or amenity spaces,

compare the shadow maps of the existing and proposed situations, and to guide further investigation of sunlight

access in later sections. They were also used to inform the design development of the scheme and to try to

maximise the sunlight levels to amenity spaces.

The maps demonstrate that following development there will be limited adverse impact on surrounding dwellings

or amenity areas and only transient overshadowing over amenity areas within the development.

Overshadowing was visualized and analysed using Suncast which is used to investigate external obstruction and

self-shading of a building by generating shading and solar insolation images from any sun position defined by

date, time, orientation, site latitude and longitude. For this evaluation the following coordinates were used;

The following coordinates were uses for the evaluation;

Latitude: 53°18'07.3"n

Longitude: 6°11'28.4"w

BRE 209 uses the equinox, March 21st for evaluation of sunlight, skylight and daylight. The statistics of Met

Eireann show that during December, Dublin receives a mean daily duration of 1.7 hours of sunlight (only 22% of

potential sunlight hours) and during June, receives a mean daily duration of 6.4 hours of sunlight (38% of

potential sunlight hours). The summer solstice is the best case scenario with minimal shadows due to the height of

the sun, and winter solstice is the worst case, when it is common for large areas of the ground to be in shadow

due to the suns low angle and shorter days. Therefore for consistency and in line with BRE guidance we have

also used March 21st in overshadowing analysis to represent the average condition across the year. For

completeness we have also included diagrams for June 21st, 21st September and 21st December.

Regarding the assessment of nearby sensitive receptors, there are houses along the western edge on St.

Margaret’s which have been considered. These were evaluated further in terms of Vertical Sky Component,

Annual Probable Sunlit Hours. Please refer to sections 3 and 4. It should be noted that these dwellings have

mature trees and vegetation shielding them from the proposed development site, the presence of this which will

eliminate any potential impact due to their overshadowing effect however, to determine the worst case scenario

for the purpose of this evaluation we have not included the trees.

20841


Shadow Diagrams for 21 s t March

Exist ing

8:00 09:00 10:00

Proposed

08:00 09:00 10:00

21 M ar 08: 00

N

sun

Suncast image:

View time = 21 Mar 08:00

Site Latitude = 51.48

Longitude diff. = -0.45

Model Bearing = 0.00

Sun: azi = 112.48 alt = 16.43

Eye: azi = 180.00 alt = 90.00

21 M ar 09: 00

N

sun

Suncast image:





Sun: azi = 125.95 alt = 24.58

Eye: azi = 180.00 alt = 90.00

21 M ar 10: 00

N

sun

Suncast image:





Sun: azi = 141.13 alt = 31.35

Eye: azi = 180.00 alt = 90.00

21 M ar 08: 00

N

sun

Suncast image:





Sun: azi = 112.48 alt = 16.43

Eye: azi = 180.00 alt = 90.00

21 M ar 09: 00

N

sun

Suncast image:





Sun: azi = 125.95 alt = 24.58

Eye: azi = 180.00 alt = 90.00

21 M ar 10: 00

N

sunSuncast image:





Sun: azi = 141.13 alt = 31.35

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

11:00 12:00 13:00

Proposed

11:00 12:00 13:00

21 M ar 11: 00

N

sun

Suncast image:





Sun: azi = 158.28 alt = 36.06

Eye: azi = 180.00 alt = 90.00

21 M ar 12: 00

N

sun

Suncast image:





Sun: azi = 176.94 alt = 38.07

Eye: azi = 180.00 alt = 90.00

21 M ar 13: 00

N

sun

Suncast image:





Sun: azi = 195.84 alt = 37.03

Eye: azi = 180.00 alt = 90.00

21 M ar 11: 00

Nsun

Suncast image:





Sun: azi = 158.28 alt = 36.06

Eye: azi = 180.00 alt = 90.00

21 M ar 12: 00

N

sunSuncast image:





Sun: azi = 176.94 alt = 38.07

Eye: azi = 180.00 alt = 90.00

21 M ar 13: 00

N

sun

Suncast image:





Sun: azi = 195.84 alt = 37.03

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

14:00 15:00 16:00

Proposed

14:00 15:00 16:00

21 M ar 14: 00

N

sun

Suncast image:





Sun: azi = 213.57 alt = 33.12

Eye: azi = 180.00 alt = 90.00

21 M ar 15: 00

N

sun

Suncast image:





Sun: azi = 229.38 alt = 26.93

Eye: azi = 180.00 alt = 90.00

21 M ar 16: 00

N

sun

Suncast image:





Sun: azi = 243.34 alt = 19.16

Eye: azi = 180.00 alt = 90.00

21 M ar 14: 00

Nsu

n

Suncast image:





Sun: azi = 213.57 alt = 33.12

Eye: azi = 180.00 alt = 90.00

21 M ar 15: 00

N

sun

Suncast image:





Sun: azi = 229.38 alt = 26.93

Eye: azi = 180.00 alt = 90.00

21 M ar 16: 00

N

sun

Suncast image:





Sun: azi = 243.34 alt = 19.16

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

1700 18:00

Proposed

1700 18:00

21 M ar 17: 00

N

sun

Suncast image:





Sun: azi = 255.96 alt = 10.42

Eye: azi = 180.00 alt = 90.00

21 M ar 18: 00

N

sun

Suncast image:





Sun: azi = 267.86 alt = 1.18

Eye: azi = 180.00 alt = 90.00

21 M ar 17: 00

N

sun

Suncast image:





Sun: azi = 255.96 alt = 10.42

Eye: azi = 180.00 alt = 90.00

21 M ar 18: 00

N

sun

Suncast image:





Sun: azi = 267.86 alt = 1.18

Eye: azi = 180.00 alt = 90.00

20841


Shadow Diagrams for 21s t June

Exist ing

08:00 09:00 10:00

Proposed

08:00 09:00 10:00

21 Jun 08: 00

N

sun

Suncast image:

View time = 21 Jun 08:00




Sun: azi = 97.26 alt = 36.15

Eye: azi = 180.00 alt = 90.00

21 Jun 09: 00

N

sun

Suncast image:





Sun: azi = 110.98 alt = 45.19

Eye: azi = 180.00 alt = 90.00

21 Jun 10: 00

N

sun

Suncast image:





Sun: azi = 128.10 alt = 53.32

Eye: azi = 180.00 alt = 90.00

21 Jun 08: 00

N

sun

Suncast image:





Sun: azi = 97.26 alt = 36.15

Eye: azi = 180.00 alt = 90.00

21 Jun 09: 00

N

sun

Suncast image:





Sun: azi = 110.98 alt = 45.19

Eye: azi = 180.00 alt = 90.00

21 Jun 10: 00

N

sun

Suncast image:





Sun: azi = 128.10 alt = 53.32

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

11:00 12:00 13:00

Proposed

11:00 12:00 13:00

21 Jun 11: 00

N

sun

Suncast image:





Sun: azi = 150.53 alt = 59.43

Eye: azi = 180.00 alt = 90.00

21 Jun 12: 00

N

sun

Suncast image:





Sun: azi = 178.39 alt = 61.96

Eye: azi = 180.00 alt = 90.00

21 Jun 13: 00

N

sun

Suncast image:





Sun: azi = 206.63 alt = 59.92

Eye: azi = 180.00 alt = 90.00

21 Jun 11: 00

N

sun

Suncast image:





Sun: azi = 150.53 alt = 59.43

Eye: azi = 180.00 alt = 90.00

21 Jun 12: 00

N

sun

Suncast image:





Sun: azi = 178.39 alt = 61.96

Eye: azi = 180.00 alt = 90.00

21 Jun 13: 00

N

sun

Suncast image:





Sun: azi = 206.63 alt = 59.92

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

14:00 15:00 16:00

Proposed

14:00 15:00 16:00

21 Jun 14: 00

N

sun

Suncast image:





Sun: azi = 229.73 alt = 54.12

Eye: azi = 180.00 alt = 90.00

21 Jun 15: 00

N

sun

Suncast image:





Sun: azi = 247.34 alt = 46.15

Eye: azi = 180.00 alt = 90.00

21 Jun 16: 00

N

sun

Suncast image:





Sun: azi = 261.34 alt = 37.17

Eye: azi = 180.00 alt = 90.00

21 Jun 14: 00

Nsu

n

Suncast image:





Sun: azi = 229.73 alt = 54.12

Eye: azi = 180.00 alt = 90.00

21 Jun 15: 00

N

sun

Suncast image:





Sun: azi = 247.34 alt = 46.15

Eye: azi = 180.00 alt = 90.00

21 Jun 16: 00

N

sun

Suncast image:





Sun: azi = 261.34 alt = 37.17

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

17:00 18:00

Proposed

17:00 18:00

21 Jun 17: 00

N

sun

Suncast image:





Sun: azi = 273.38 alt = 27.85

Eye: azi = 180.00 alt = 90.00

21 Jun 18: 00

N

sun

Suncast image:





Sun: azi = 284.52 alt = 18.64

Eye: azi = 180.00 alt = 90.00

21 Jun 17: 00

N

sun

Suncast image:





Sun: azi = 273.38 alt = 27.85

Eye: azi = 180.00 alt = 90.00

21 Jun 18: 00

N

sun

Suncast image:





Sun: azi = 284.52 alt = 18.64

Eye: azi = 180.00 alt = 90.00

20841


Shadow Diagrams for 21 s t September

Exist ing

8:00 09:00 10:00

Proposed

08:00 09:00 10:00

21 M ar 08: 00

N

sun

Suncast image:





Sun: azi = 112.48 alt = 16.43

Eye: azi = 180.00 alt = 90.00

21 M ar 09: 00

N

sun

Suncast image:





Sun: azi = 125.95 alt = 24.58

Eye: azi = 180.00 alt = 90.00

21 M ar 10: 00

N

sun

Suncast image:





Sun: azi = 141.13 alt = 31.35

Eye: azi = 180.00 alt = 90.00

21 M ar 08: 00

N

sun

Suncast image:





Sun: azi = 112.48 alt = 16.43

Eye: azi = 180.00 alt = 90.00

21 M ar 09: 00

Nsun

Suncast image:





Sun: azi = 125.95 alt = 24.58

Eye: azi = 180.00 alt = 90.00

21 M ar 10: 00

N

sunSuncast image:





Sun: azi = 141.13 alt = 31.35

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

11:00 12:00 13:00

Proposed

11:00 12:00 13:00

21 M ar 11: 00

N

sun

Suncast image:





Sun: azi = 158.28 alt = 36.06

Eye: azi = 180.00 alt = 90.00

21 M ar 12: 00

N

sun

Suncast image:





Sun: azi = 176.94 alt = 38.07

Eye: azi = 180.00 alt = 90.00

21 M ar 13: 00

N

sun

Suncast image:





Sun: azi = 195.84 alt = 37.03

Eye: azi = 180.00 alt = 90.00

21 M ar 11: 00

Nsun

Suncast image:





Sun: azi = 158.28 alt = 36.06

Eye: azi = 180.00 alt = 90.00

21 M ar 12: 00

N

sunSuncast image:





Sun: azi = 176.94 alt = 38.07

Eye: azi = 180.00 alt = 90.00

21 M ar 13: 00

N

sun

Suncast image:





Sun: azi = 195.84 alt = 37.03

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

14:00 15:00 16:00

Proposed

14:00 15:00 16:00

21 M ar 14: 00

N

sun

Suncast image:





Sun: azi = 213.57 alt = 33.12

Eye: azi = 180.00 alt = 90.00

21 M ar 15: 00

N

sun

Suncast image:





Sun: azi = 229.38 alt = 26.93

Eye: azi = 180.00 alt = 90.00

21 M ar 16: 00

N

sun

Suncast image:





Sun: azi = 243.34 alt = 19.16

Eye: azi = 180.00 alt = 90.00

21 M ar 14: 00

Nsu

n

Suncast image:





Sun: azi = 213.57 alt = 33.12

Eye: azi = 180.00 alt = 90.00

21 M ar 15: 00

N

sun

Suncast image:





Sun: azi = 229.38 alt = 26.93

Eye: azi = 180.00 alt = 90.00

21 M ar 16: 00

N

sun

Suncast image:





Sun: azi = 243.34 alt = 19.16

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

1700 18:00

Proposed

1700 18:00

21 M ar 17: 00

N

sun

Suncast image:





Sun: azi = 255.96 alt = 10.42

Eye: azi = 180.00 alt = 90.00

21 M ar 18: 00

N

sun

Suncast image:





Sun: azi = 267.86 alt = 1.18

Eye: azi = 180.00 alt = 90.00

21 M ar 17: 00

N

sun

Suncast image:





Sun: azi = 255.96 alt = 10.42

Eye: azi = 180.00 alt = 90.00

21 M ar 18: 00

N

sun

Suncast image:





Sun: azi = 267.86 alt = 1.18

Eye: azi = 180.00 alt = 90.00

20841


Shadow Diagrams for 21 s t December

Exist ing

8:00 09:00 10:00

Proposed

08:00 09:00 10:00

21 Dec 08: 00

N

Suncast image:

View time = 21 Dec 08:00




Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 09: 00

N

sun

Suncast image:





Sun: azi = 139.19 alt = 5.24

Eye: azi = 180.00 alt = 90.00

21 Dec 10: 00

N

sun

Suncast image:





Sun: azi = 152.01 alt = 10.52

Eye: azi = 180.00 alt = 90.00

21 Dec 16: 00

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 09: 00

Suncast image:





Sun: azi = 139.19 alt = 5.24

Eye: azi = 180.00 alt = 90.00

21 Dec 10: 00

Suncast image:





Sun: azi = 152.01 alt = 10.52

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

11:00 12:00 13:00

Proposed

11:00 12:00 13:00

21 Dec 11: 00

N

sun

Suncast image:





Sun: azi = 165.66 alt = 13.89

Eye: azi = 180.00 alt = 90.00

21 Dec 12: 00

N

sun

Suncast image:





Sun: azi = 179.82 alt = 15.07

Eye: azi = 180.00 alt = 90.00

21 Dec 13: 00

N

sun

Suncast image:





Sun: azi = 193.98 alt = 13.95

Eye: azi = 180.00 alt = 90.00

21 Dec 11: 00

Suncast image:





Sun: azi = 165.66 alt = 13.89

Eye: azi = 180.00 alt = 90.00

21 Dec 12: 00

Suncast image:





Sun: azi = 179.82 alt = 15.07

Eye: azi = 180.00 alt = 90.00

21 Dec 13: 00

Suncast image:





Sun: azi = 193.98 alt = 13.95

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

14:00 15:00 16:00

Proposed

14:00 15:00 16:00

21 Dec 14: 00

N

sun

Suncast image:





Sun: azi = 207.65 alt = 10.63

Eye: azi = 180.00 alt = 90.00

21 Dec 15: 00

N

sun

Suncast image:





Sun: azi = 220.50 alt = 5.39

Eye: azi = 180.00 alt = 90.00

21 Dec 08: 00

N

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 14: 00

Suncast image:





Sun: azi = 207.65 alt = 10.63

Eye: azi = 180.00 alt = 90.00

21 Dec 15: 00

Suncast image:





Sun: azi = 220.50 alt = 5.39

Eye: azi = 180.00 alt = 90.00

21 Dec 16: 00

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

20841


Exist ing

1700 18:00

Proposed

1700 18:00

21 Dec 08: 00

N

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 08: 00

N

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 17: 00

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

21 Dec 17: 00

Suncast image:





Sun is not up

Eye: azi = 180.00 alt = 90.00

20841


6. Sunlight to Amenity Spaces

Summary of Results for Amenity Spaces

For Cross Avenue we have carried out an evaluation of the roof terraces within the site along with the overall site.

In addition we have evaluated the gardens of adjacent dwellings on St. Margaret’s Road.

The BRE guidance is the same for both public and private amenity areas in that at least 50% of the area should

receive at least 2 hours of sunlight on March 21st.

Sunlight exposure was evaluated by generating a 1m2 grid across each amenity area and utilizing hourly solar

shading data to produce the exposure results in hours and percentage of available hours for the specified period.

To ensure an additional level of robustness for the design the adjoining gardens were evaluated, excluding the

mature trees.

The results show that all amenity spaces evaluated exceed BRE guidelines that at least 50% of an amenity area

should receive a minimum 2 hours sunlight on March 21st.

Figure 29: Areas evaluated

Figure 30: Overview of model

Within Development Site

Block Amenity Space % Area > 2hrs sunlight BRE Threshold Compliant

Block B Roof Terrace 1 97.8% 50% Yes

Roof Terrace 2 100% 50% Yes

Block C Roof terrace 100% 50% Yes

Site Grounds 94% 50% Yes

Table 12: Sunlight to amenity spaces within the proposed development

Adjacent Dwell ings

Block % Area > 2hrs sunlight > 50% receives

2 hours of

sunlight

Reduction

in sunlit

area is <

20%

Compliant

Existing Proposed Ratio

Goleen 95.4% 94.2% 98.7% Yes Yes Yes


100% 100% 100% Yes Yes Yes

2 St. Margaret’s 92.6% 88.5% 95.5% Yes Yes Yes

3 Dunamase, St Margaret’s

100% 97.8% 97.8% Yes Yes Yes

Table 13: Sunlight to surrounding residential amenity spaces

20841


Amenity Spaces within the Proposed Scheme

Block B

Figure 31; Overview of Block B

Figure 32; Block B terraces - Area receiving at least 2 hours sunlight on March 21st

Amenity Space Area Area > 2hrs sunlight BRE Threshold Compliant

(m2) (m2) (%)

Roof terrace 1 596.6 583 97.7% 50% Yes

Roof Terrace 2 273.1 273.1 100% 50% Yes

Table 14; Sunlight results for Block B

Block C

Figure 33; Overview of Block C

Figure 34; Block C terraces – Area receiving at least 2 hours sunlight on March 21st

Amenity Area Area Area > 2hrs sunlight BRE Threshold Compliant

(m2) (m2) (%)

Roof terrace 596 596 100% 50% Yes

Table 15; Sunlight results for Block C

20841


Residential Development Grounds

Figure 35; Overview

Figure 36; Area receiving at least 2 hours sunlight on March 21st

Amenity Area Area Area > 2hrs sunlight BRE Threshold Compliant

(m2) (m2) (%)

Development Grounds 8,877 8,350 94% 50% Yes

Table 16; Sunlight results for proposed development

20841


Sunlight to Adjacent Residential Amenity Spaces

Figure 37; Adjacent dwellings

Goleen

15.5

Figure 38; Sunlight to Goleen garden post development

Figure 39: Existing sunlight to Goleen garden

Dwelling Garden

Area

(m2)

% Area > 2hrs sunlight > 50% receives

2 hours of

sunlight

Reduction

in sunlit

area is <

20%

Compliant


Goleen 1,725 95.4% 94.2% 98.7% Yes Yes Yes

Table 17: Sunlight to Goleen garden

20841


Litt le Oaks, 1 St. Margaret’s

1

Figure 40: Sunlight to 1 St. Margaret’s garden post development

Figure 41: Existing sunlight to Goleen garden

Dwelling Garde

n Area

(m2)

% Area > 2hrs sunlight > 50%

receives 2

hours of

sunlight

Reduction

in sunlit

area is <

20%

Compliant


Little Oaks 1 St. Margaret’s

358 100% 100% 100% Yes Yes Yes

Table 18: Sunlight to 1 St. Margaret’s garden

2 St. Margaret’s


Figure 43: Existing sunlight to 1 St. Margaret’s garden

Dwelling Garden

Area

(m2)


receives 2

hours of

sunlight

Reduction in

sunlit area is

< 20%

Compliant


2 St. Margaret’s

218 92.6% 88.5% 95.5% Yes Yes Yes


20841




Figure 45: Existing sunlight to 3 St. Margaret’s garden

Dwelling Garden

Area

(m2)


receives 2

hours of

sunlight

Reduction

in sunlit

area is <

20%

Compliant


3 Dunamase St. Margaret’s

198 100% 97.8% 97.8% Yes Yes Yes


20841


Appendix 1 – Point Cloud Survey Drawing

20841


sunlight report cross avenue residential development

Documents