#ukphc18 fulford passivhaus designing, building & beyond · and lighting to central staircase....

#UKPHC18

Fulford PassivhausDesigning, building &

beyondKarin de Vries (client / owner) and

Phil Bixby (architect / Passivhaus Designer)

Why Passivhaus?

Osborne House• 1920s construction

• 1960s extensions

• 1990s conservatory

Single glazed windows NNo windows on S elevationConservatoryLack of insulationBoys sharing bedroom+Morning sunrise

Development of the design

• Original proposals – retrofit and extension

Development of the design

• Original proposals – Osborne House – retrofit and extension

• Got planning permission!

Development of the design

• Original proposals – Osborne House – retrofit and extension

• Got planning permission!

•BUT..

Development of the design

•BUT..• Couldn’t get Passivhaus performance

Development of the design

•BUT..• Couldn’t get Passivhaus performance

• Compromises over layout

Development of the design

•BUT..• Couldn’t get Passivhaus performance

• Compromises over layout

• It was work to an existing building so it would cost 20% extra as we’d have to pay VAT

Development of the design

• Started from scratch with new-build proposal

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

• …plus shading to south-facing glazing, along with additional brise-soleil

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

• …plus shading to south-facing glazing, along with additional brise-soleil

• Careful modelling to try to avoid overheating in summer…

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

• …plus shading to south-facing glazing, along with additional brise-soleil

• Careful modelling to try to avoid overheating in summer…

• While allowing as much daylightingas possible in winter

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

• …plus shading to south-facing glazing, along with additional brise-soleil

• North elevation glazing minimised – just views from rooms and lighting to central staircase

Development of the design

• Started from scratch with new-build proposal

• Perfect orientation – roof designed to give maximum area for PVs…

• …plus shading to south-facing glazing, along with additional brise-soleil

• North elevation glazing minimised – just views from rooms and lighting to central staircase

• Got planning permission (some objections over appearance, but smaller than approved extension scheme)

Construction process

• Limited budget = > tough choices

Construction process

• Limited budget = > tough choices

• After weather tight stage => we took over project management

Construction process

• Limited budget = > tough choices

• After weather tight stage => we took over project management

• Sometimes cheap is not economical =>

Construction process

• Limited budget = > tough choices

• After weather tight stage => we took over project management

• Sometimes cheap is not economical =>

• Airtightness took a lot longer than expected due to initial cheaper choice.

Construction process

• Limited budget = > tough choices

• After weather tight stage => we took over project management

• Sometimes cheap is not economical =>

• Airtightness took a lot longer than expected due to initial cheaper choice.

• Cheap render now needs regular maintenance, expensive in the long run

Construction process

• Limited budget = > tough choices

• After weather tight stage => we took over project management

• Sometimes cheap is not economical =>

• Airtightness took a lot longer than expected due to initial cheaper choice.

• Cheap render now needs regular maintenance, expensive in the long run

• No compromise on renewables =>

• The house creates an energy income because of generating electricity resulting in a yearly profit of over £1,000

Airtightness

Specification choices

• Hybrid foundation comprising perimeter strip foundation to carry blockwork external leaf

Specification choices

• Hybrid foundation comprising perimeter strip foundation to carry blockwork external leaf… plus…

• Slab on polystyrene insulation

• …plus local pad foundations where point loads

• Suitable grades of polystyrene used to carry timber frame loads

Specification choices

• Suitable grades of polystyrene used to carry timber frame loads

• …while also minimising thermal bridging

Specification choices

• Wall construction – multi-layer

Specification choices

• Wall construction – multi-layer

• 140mm timber frame for low cost

• External rendered blockwork for low cost

• Multiple layers of insulationto reduce thermal bridging

Specification choices

Energy and the sun

South facing:Large windows

North facing:Small windows

Energy andthe sun• Passive solar gain

windows

larger than

heat losses windows

Solar panels PHPP forecast of solar panel generation:8466 kWh or 89 kWh/m2

Generation2016: 9360 kWh2017: 9140 kWh2018: 8990 kWh (so far)

• October PHPP:• Heating demand:

68 kWh. • The house has

never needed heating in October so far.

• October 2018• Hot water

requirement for family with 3 teenagers (!!!):

• From solar panels 199.5 kWh

• From grid: 42 kWh

Hot water requirement

• PHPP exaggerates the use for hot water for our 5 person household

• Actual use is on average approx. 7.5 kWH per day.

• Immersun diversion in the months March to October is virtually 100 %, i.e. all water heating from the solar panels.

• In October: 200 kWh from solar panels and 42 kWh from grid.

• November-February: No import from grid on sunny days.

Hot water cylinder and Immersuns

20 Dec 2015: Solar generation 18 kWh • Enough solar generation to heat up hot water cylinder (6.5-8 kWh)• Passive solar gain and body heat to keep house warm to 20 0C.• Plus: kettle, dish washer, washing machine etc

Solar Generation 2016, export and import

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Solar use

Electricity use 2016:From pv: 4024 kWh (21.6 kWh/m2)From grid: 1237 kWh*(6.6 kWh/m2)OR: 5186 kWh*(27.9 kWh/m2)Total: 5261 kWh (28.3 kWh/m2)OR: 9210 kWh (49.5 kWh/m2)*incl electric car

Solar generation 2016: 9200 kWhSolar pv personal use: 4024 kWhSolar pv export: 5176 kWh

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Import

Solar use

• Design of house pre-dates Passivhaus Plus and Premium designations

Passivhaus certification

Passivhaus certification

• Design of house pre-dates Passivhaus Plus and Premium designations

• Went through usual certification process

• Airtightness testing and evidence of construction according to approved specification

• Design of house pre-dates Passivhaus Plus and Premium designations

• Went through usual certification process

• Airtightness testing and evidence of construction according to approved specification

• During certification process the higher standards were introduced

• Realised that house qualified as Passivhaus Plus – the first to be certified in the UK!

Passivhaus certification

Life in a Passivhaus PlusHeating:MVHR recycles 84 per cent of exhaust air heat.1 kW postheater on mvhr supply pipe4 towel radiator (120W, 400W, 500W, 600W)1 radiator in sitting room 1.2kW since 2016.Temperature is stable.

Comfort

Some sample temperature data from January 2016 (Emonpi)It shows the external temperature varying between about 3 and 14 degrees while the internal temperature remains between 20 and 22 degrees.*

*This was before the post heater was working properly and

before any other heating was installed.

After a week away over Christmas 2015- no heating on

Need for warmth

• Sunny winter days create passive solar gain and solar pv.

• Cloudy rainy days =>

Need for warmth

• Sunny winter days create passive solar gain and solar pv.

• Cloudy rainy days => Electricity from grid needed to provide warm water.

Need for warmth

• Sunny winter days create passive solar gain and solar pv.

• Cloudy rainy days => Electricity from grid needed to provide warm water.

• Cold cloudy days => Grid electricity required for keeping the house warm and providing hot water.

Edible garden

Towards zero carbon