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

 

Bucks PH15 Passivhaus project .

 

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

 

Bucks PH15 Passivhaus project .

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

 

Bucks PH15 Passivhaus project .

 

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

Bucks PH15 Passivhaus project .

 

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.

 

Falmouth PH15 Passivhaus project - Accoya wood balcony to front elevation

 

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.

 

Eigg PH15 Passivhaus project - view over-looking Cleadale

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.

 

Eigg PH15 Passivhaus project - view over-looking Cleadale

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.

Eigg PH15 Passivhaus project - view over-looking Cleadale

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.

 

Beltane PH15 Passivhaus project - cgi impression

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.

Hickling PH15 Passivhaus project - rear elevation

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@50Pa

Contractor: Waterhead Projects Ltd. 

 

Northenhay concept design

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)

 

Compton rear elevation - PH15 Passivhaus project

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.

 

Dart House front elevation - PH15 Passivhaus project

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

 

 

Riverways front elevation

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.

elevations

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.

projects at the beginning - view of plans

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.

Ha Ha artists impression

 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

 

Completed house viewed from the High Street

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

The entrance and glass canopy
Winners of the 2013 Passivhaus Trust Awards
view across the living roof
general view of house
North elevation
RIBA logo
Passivhaus Trust Member
Anti Greenwashing Charter logo
certified passivhaus consultant
Buildoffsite Property Assurance Scheme (BOPAS) was developed to address these concerns and perceived risks associated with innovative construction. BOPAS is recognised by the principal mortgage lenders as providing the necessary assurance underpinned by a warranty provision, that the property will be readily mortgageable for at least 60 years.