A selection of PH15 projects showing how versatile the PH15 system is in transforming different designs and project types into low carbon and Passivhaus reality. PH15 optimises energy efficiency, use of low embodied carbon materials and ensures a robust approach in a changing climate.
PH15 accurately predicts energy use, overheating percentage and will also measure embodied carbon from 2020 – the headline figures are shown below for a variety of PH15 projects. True sustainability is built on reliable energy modelling, PH15 makes use of the PHPP software, which is proven to be accurate.
Dorsal House
New build detached house designed by Thiss Studio near Epping Forest. Three storey on a very tight site. Aiming for Passivhaus Plus.
Passivhaus and Carbon/Energy statistics:
TFA 168.5 m². Building Form Factor 3.3 with average wall and roof U-value 0.097 W/m²K, floor 0.068 W/m²K.
Overheating percentage 2.7%. Predicted Heating Demand 16.9 kWh/m².yr. Heating load 10.0 W/m².
Embodied Carbon PH15 System inc foundations: A1-A4 27.7 tonnes
Meets RIBA 2030 target for Operational Energy and Embodied Carbon.
Completion: Spring 2024
Contractor: Waltons Construction Ltd
Dibden Purlieu
New build detached house designed by Haydn Bennett.
Passivhaus and Carbon/Energy statistics:
TFA 150.8 m². Building Form Factor 3.5 with average wall and roof U-value 0.097 W/m²K, floor 0.076 W/m²K.
Overheating percentage 1.7%. Predicted Heating Demand 12.9 kWh/m².yr. Heating load 9.97 W/m². .
Embodied Carbon PH15 System inc foundations: A1-A4 27.7 tonnes
Meets RIBA 2030 target for Operational Energy and Embodied Carbon.
Completed: September 2023
Contractor: YourHaus Ltd
South Downs
New build detached house designed Meloy Architecture + Design. Aiming for Passivhaus Certified Classic.
Passivhaus and Carbon/Energy statistics:
TFA 249.5 m². Building Form Factor 3.98 with average wall and roof U-value 0.097 W/m²K, floor 0.109 W/m²K, and average installed whole window/door U values 0.77 W/m²K. Overheating percentage 2.7%.
Predicted Heating Demand 14.9 kWh/m².yr. Heating load 9.4 W/m².
AC/hr @ 50 Pa: 0.32
Embodied Carbon PH15 System inc foundations: A1-A4 27.7 tonnes
Meets RIBA 2030 target for Operational Energy and Embodied Carbon.
Completed: May 2022
Prestwood, Bucks
New build detached house designed by Phil Bailey (Contour Architecture). Three storey infill on a tight site with a mixture of render and cladding. Whist the house has a fairy compact footprint there was space within to create some interesting spaces. Passivhaus Certified Classic.
Passivhaus and Carbon/Energy statistics:
TFA 157.5 m². Building Form Factor 2.8 with average wall and roof U-value 0.103 W/m²K, floor 0.1 W/m²K, and average installed whole window/door U values 0.9 W/m²K. Overheating percentage 0.4%. Predicted Heating Demand 14.9 kWh/m².yr. Heating load 9.4 W/m². .
Embodied Carbon PH15 System inc foundations: A1-A4 27.7 tonnes
Meets RIBA 2030 target for Operational Energy and Embodied Carbon.
Completed: September 2021
Contractor: Symon Szczepanski
Falmouth
New build detached house designed by Dow Jones Architects. Externally clad with Accoya, a highly weather resistant and stable, modified timber. Standing seam roof. The large, full width balcony provides shading to the south facing front elevation.
Passivhaus and Carbon/Energy statistics:
TFA 240.4 m². Building Form Factor 2.6 with average wall and roof U-value 0.103 W/m²K, floor 0.1 W/m²K, and average installed whole window/door U values 0.9 W/m²K. Overheating percentage 1%. Predicted Heating Demand 10.9 kWh/m².yr. Heating load 7.9 W/m². Renewable energy demand 42 kWh/m²a.
Embodied Carbon PH15 System inc foundations: A1-A4 47 tonnes
Meets RIBA 2030 target for Operational Energy and Embodied Carbon.
On site: Feb 2021
Contractor: Berryman Construction Ltd.
Saorsa, Ardnamurchan
New build on the Ardnamurchan peninsular aiming to be net zero carbon. The PH15 element of the build is off-set by us through tree planting. This site is almost as isolated as our project on Eigg with all materials arriving via the narrow lane that runs out to Ardnamurchan lighthouse – featuring toward the end of the shipping forecast so you may be asleep by the time they mention it.
Passivhaus and Carbon/Energy statistics:
TFA 114.5 m². Building Form Factor 4.0 with average wall and roof U-value 0.095 W/m²K, floor 0.07 W/m²K, and average installed whole window/door U values 0.9 W/m²K. Overheating percentage 1%. Predicted Heating Demand 16.8 kWh/m².yr. Heating load 9.84 W/m². Renewable energy demand 39 kWh/m²a.
Embodied Carbon PH15 System inc foundations: A1-A3 21.7 tonnes
On site: June 2021
Contractor: Michael Faryma Joinery Contractors Ltd.
Castle Hill, Herts
New build 5 bed detached house (treated floor area 239 sqm) designed by architect Phil Bailey (Contour Architecture) and developed to the passivhaus standard using the PH15 Passivhaus System. External finishes of lime render and timber cladding with slated and standing seam metal roofs
Passivhaus and Carbon/Energy statistics:
TFA 239 m². Building Form Factor 3.2 with average wall and roof U-value 0.1 W/m²K, floor 0.09 W/m²K, and average installed whole window/door U values 0.9 W/m²K. Overheating percentage 2.3%. Predicted Heating Demand 14.1 kWh/m².yr.
Embodied Carbon PH15 shell A1-A3: 26.5 t CO2e
Contractor: Jigsaw Design & Construction Ltd.
Oakfield Farm
Replacement barn under ‘Part Q’ planning legislation. Design by Passivhaus Homes Ltd. Retention of existing concrete portal. Client has chosen to have external blinds on all windows. The clients are interested in permaculture, as well as low energy housing.
Passivhaus and Carbon/Energy statistics:
TFA 144 m². Building Form Factor 3.0 with average wall and roof U-value 0.1 W/m²K, floor 0.11 W/m²K, and average installed whole window/door U values 0.92 W/m²K. Overheating percentage under 2%. Predicted Heating Load 8.9 W/m². Renewable energy generation 12 kW photovoltaic array. Designed to Passivhaus Plus standard.
Contractor: Self build.
Beltane Drive, SW19
New build detached house (treated floor area 370 sqm), designed by architect Tim Gledstone of Squire & Partners and developed to the passivhaus plus standard using the PH15 Passivhaus System. Construction due to start February 2020.
External finish Lime render with standing seam pitched roofs over a complex timber ‘wing’ construction. Windows and doors Katzbeck Flat range.
Passivhaus & Carbon/Energy statistics:
TFA 370 m². Building Form Factor 2.7 with average wall U-value 0.101 W/m²K, floor 0.088 W/m²K, roof 0.096 W/m²K, and average installed whole window/door U values 0.92 W/m²K. Overheating percentage 0.7%. Predicted Heating Demand 8.66kWh/m².yr.
Contractor: Beltane Construction Ltd.
Hickling, Norfolk
New build pair of semi-detached houses (treated floor area 370 sqm), design by architect Fran Bradshaw and developed to the Passivhaus standard using the PH15 Passivhaus System.
External finish lime render with tiled pitched roofs. Windows and doors GBS Ultra range.
Passivhaus & Carbon/Energy statistics:
TFA 370 m². Building Form Factor 3.15 with average wall U-value 0.102 W/m²K, floor 0.088 W/m²K, roof 0.097 W/m²K, and average installed whole window/door U values 0.92 W/m²K. Overheating percentage 3.1%. Predicted Heating Demand 14.2 kWh/m².yr.
Airtightness results 0.33 and 0.25 ach @ 50Pa
Contractor: Self build. Project managed by Georg Herrmann.
Northenhay, Totnes
Bespoke new build detached house (treated floor area, 205 sqm), concept design by Studio DC Architects, and then detailed to the Passivhaus standard by PHH using the PH15 System. Construction started February 2019.
External finishes are a mix of lime render and vertical timber boarding. Zinc pitched roofs with first floor terrace to side. Windows and doors Katzbeck CombinaPassiv range.
Passivhaus and Carbon/Energy statistics:
TFA 205 m² Building Form Factor 3.0 with average wall U-value 0.11 W/m²K, floor 0.078 W/m²K, roof 0.096 W/m²K, and average installed whole window and door U values 1.0 W/m²K. Predicted Heating Demand 13.5 kWh/m².yr Overheating percentage 0.3%.
GIA circa 230m².
Initial air-tightness test result 0.2 ach@50PaContractor: Waterhead Projects Ltd.
Compton, Forge Road, Langley.
Bespoke new build detached house (net floor area 196 sqm), designed and project managed by architect Haydn Bennett (www.lowenergyhouse.design) and constructed using the PH15 System. Meets Passivhaus Plus standard with an Air Source Heat Pump (clients plan to fit this in next 5-10 years).
External finishes are a mix of lime render and ThermoWood vertical cladding. South facing roof zinc, north facing roof tiled. Windows and doors Katzbeck Design range. Renewables: 3.96 kW photovoltaic array on the roof.
Passivhaus and Carbon/Energy statistics:
TFA 184 m² Building Form Factor 2.7 with average wall U-value 0.101W/m²K, floor 0.135W/m²K, roof 0.100W/m²K, and average installed whole window and door U values 0.90W/m²K.
Predicted Heating Demand 8 kWh/m².yr. Overheating percentage 0.1%.
GFA 196m². Final air tightness test result 0.26 ach@50Pa.
Construction by F Noble & Sons Ltd, Completed Autumn 2019.
Certified Passivhaus Classic (has a gas wall mounted boiler)
Dart House, Devon
Bespoke new build detached house (net floor area 298 sqm) on a sloping site, designed to planning stage by Passivhaus Homes and then detailed using the PH15 System. Construction started on site March 2018 by Waterhead Projects. This is our most complex Passivhaus form to date and illustrates that airtightness can be achieved on more challenging house forms. Clients like very warm house so slightly higher overheating percentage suits them, it is still well below Passivhaus limit of 10%.
External finishes are a mix of lime render and western red cedar boarding. Windows and doors Katzbeck CombinaPassiv range.
Passivhaus and Carbon/Energy statistics:
TFA 270.1 m² Building Form Factor 3.93 with average wall U-value 0.093W/m²K, floor 0.11W/m²K, roof 0.083W/m²K, and average installed whole window/door U values 0.89W/m²K. Overheating frequency 4.8%.
Predicted Heating Demand 12.9 kWh/m².yr
GFA 298m². Air tightness test result 0.35 ach @ 50Pa.
Construction by Waterhead Projects Ltd. Completed April 2019.
Riverways, Devon
Bespoke new build detached house (net floor area 208sqm) designed to planning stage by architect Chris Donoghue and then detailed and constructed using the PH15 System – the design needed some modifications by us to hit the Passivhaus standard. Construction started on site April 2015 by Passivhaus Homes Ltd.
External finishes are a mix of lime render and western red cedar boarding. Windows and doors Katzbeck Linea range.
Passivhaus and Carbon/Energy statistics:
TFA 193.8 m² Building Form Factor 2.79 with average wall U-value 0.09W/m²K, floor 0.11W/m²K, roof 0.10W/m²K, and average installed whole window/door U values 0.88W/m²K.
GFA 208m², PH15 System components £115,000
Constructed by Passivhaus Homes Ltd.
Completed Spring 2016.Certified Passivhaus
Akerman Rd, London SW9
A social housing project for Lambeth Council. The site is an urban infill on a typical London street. Design by Anne Thorne Architects. Finishes are a mix of lime render, brick entrance porches, brick slips and reconstituted slate roofs. This project is first use of the PH15 for social housing provision. Cost of PH15 was under £450/m², extremely cost effective, achieved in part due to the excellent Form Factor (1.8) from three storey terrace layout. A post occupancy study by UCL highlighted health benefit outcomes.
“You could hear the raspiness in her cough… she doesn’t suffer from that anymore — since we’ve been here, she doesn’t cough in the night.” Passivhaus Plus Magazine
Passivhaus and Carbon/Energy Statistics:
TFA 371sqm. Form Factor 1.8, with U-values of roof 0.108 W/m2K, walls 0.105 W/m2K floor 0.106 W/m2K. Heating load 7.9W/m2. Predicted Heating demand 9.1 kWh/m²a. Airtightness test results: 0.34, 0.39 and 0.4 ach @ 50Pa. Overheating frequency 1.9%.
Construction by Sandwood Construction Ltd.
Completed December 2016.
Certified Passivhaus.
Littlepits Passivhaus (Plus)
A five bedroom detached house. The design had to meet the exacting Chiltern’s Design Guide, addressing planning concerns on visual impact within its Green Belt setting. The house is a mix of lime render, brick slip with lime mortar, and oak feather edge cladding. There are also two traditional green oak verandas. The house incorporates a ‘Glatthaar’ basement system which is within the Passivhaus envelope. Littlepits is now one of the most airtight houses in the UK at 0.07 ach @ 50Pa. Shortlisted for Association of Sustainable Building Products Awards 2019 (Excellence in Sustainability).
Passivhaus Plus or Net Zero Operational Carbon Statistics:
TFA 317sqm
Form Factor 2.43 with average wall/roof U value 0.085W/m2K, floor 0.07W/m2K, average whole window/door U values from 1.02-0.85W/m2K. Heating demand 11.1 kWh/m²a, heating load 7.3 W/m2. Final air-tightness result 0.07 ach@50Pa. PV: 7kW peak array. Overheating percentage 1%.
Construction by Jigsaw Design and Construction Ltd.
Completed December 2017.
Ha Ha House, Torquay
Designed by architect Richard Maddock, Director of Kay Elliott Architects for his own home, this is a single storey modern design sited in front of an old stone retaining wall, creating a striking juxtaposition of old and new.
Passivhaus Homes collaborated on modifications to the original design to bring it up to Passivhaus performance standards, and then detailed the construction package using our PH15 System.
External finishes are lime render and wood cladding with a living roof. Windows and doors are Katzbeck Linea.
Passivhaus and Carbon/Energy Statistics:
TFA 133sqm
Form Factor 4.1, with U-values of walls and roof 0.076W/m2K, floor 0.071W/m2K. Heating load 9.8W/m2. The single storey design makes getting to Passivhaus a challenge (see the poor form factor), but good junction details achieved by the PH15 System resulted in negative linear cold bridges.
GIA 139m², PH15 System components £79,000
Completed Autumn 2016. Construction by Passivhaus Homes Ltd.
Tring Passivhaus, Chilterns
This detached 3-bed house (net floor area 122sqm) is to be built in the rear garden of a house in the High Street Conservation Area in Tring town. The house is a modification of our generic 3-bed house using the Passivhaus Homes PH15 System. External finishes are a mix of lime render, timber cladding with plain clay tiling on the roof with oak end rafters. Specification includes a Lacuna folding/sliding screen door and Katzbeck windows.
Passivhaus and Carbon/Energy Statistics:
TFA 110sqm. Form Factor 3.2 with average U-values of walls and roof 0.08W/m2K, floor 0.07W/m2K. Space heating demand 13.6 kWh/sqm.yr
GIA 122m². PH15 System components £79,917.00.
Air test result 0.3 ach @ 50Pa.
Completed Summer 2016. Construction by RAK Construction Ltd.
Certified Passivhaus
Totnes Passivhaus
One of the UK’s first Certified Passivhaus refurbishment projects being a hybrid retrofit with new build extension achieving the full passivhaus standard. The extension is made from timber frame, uses recycled newspaper insulation and has a living roof. The house also has a photovoltaic array and solar hot water panels. The design achieves below the 15kWh/sqm requirement for space heating (90% less than the average UK) Total Primary measured energy in use is 75.8KWh/sqm.a The project was completed in July 2011 – the final air tightness test was an impressive 0.19 ach at 50 Pa (Passivhaus standard is 0.6 ach). This makes Hunters Moon the most leak free retrofit house in the UK!
Passivhaus and Carbon/Energy Statistics:
TFA 162sqm. Form Factor 2.62, with U-values of walls and roof 0.01W/m2K, design space heating demand: 13.3kWh/m² per annum; heating load 9.3W/m².
Completed 2011
Certified Passivhaus and Winner of the 2013 Passivhaus Trust Awards
