Hounslow Passivhaus Retrofit
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as PDF This social housing retrofit by bere:architects, will be Enerphit passivhaus making use of external insulation, new windows, and heat recovery ventilation to ensure fresh air at the same time as very low heat loss. Specific heat energy requirements will be reduced by 95%, while alsominimizing primary energy use. The existing property has an abnormally high energy demand asassessed using the Passivhaus Planning Package (PHPP). These large values are in part due to a complete absence of loft insulation. The main objectives of the project are to show that deepenergy cuts are possible with social housing stock. As UK exposure to and experience of Passivhaus grows, we aim to show that improved thermal comfort, reduced energy bills and lower CO2 emissions are possible for millions of people in existing houses.
Hounslow Passivhaus Retrofit : Project images
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Energy and fuel use
Measured data from renewable generation is not yet available.
Fuel use
| Pre-development | Forecast | Measured | |
| Electricity use | 2728 kWh/yr | 1591 kWh/yr | - |
|---|---|---|---|
| Natural gas use | 45658 kWh/yr | 2859 kWh/yr | - |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 705 kWh/m².yr | 86 kWh/m².yr | - |
|---|---|---|---|
| Annual CO₂ emissions | 131 kg CO₂/m².yr | 18 kg CO₂/m².yr | - |
| Annual space heat demand | 401 kWh/m².yr | 22 kWh/m².yr | - |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| Renewables Technology | - | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | 86 kWh/m².yr | - |
| Annual CO₂ emissions offset by renewable generation | 18 kg CO₂/m².yr | - |
Calculation and targets
| Whole house energy calculation method | PHPP |
|---|---|
| Other whole house calculation method | - |
| Energy target | Retrofit for the Future |
| Other energy targets | - |
| Forecast heating load | 12 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | - | - |
Project description
| Stage | Under construction |
|---|---|
| Start date | 15 September 2010 |
| Occupation date | |
| Location | London England |
| Build type | Refurbishment |
| Building sector | Public Residential |
| Property type | Semi-Detached |
| Construction type | Solid Brick |
| Other construction type | 230mm thick |
| Party wall construction | 230mm solid brick |
| Floor area | 84.2 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |
Project Team
| Organisation | bere:architects |
|---|---|
| Project lead person | bere:architects |
| Landlord or Client | Southern Housing |
| Architect | bere:architects |
| Mechanical & electrical consultant | Alan Clarke |
| Energy consultant | Alan Clarke |
| Structural engineer | Galbraith Hunt Pennington |
| Quantity surveyor | e Griffin Consulting |
| Consultant | |
| Contractor |
Design strategies
| Planned occupancy | Two People |
|---|---|
| Space heating strategy | Heated through the air with mechanical heat recovery ventilation. |
| Water heating strategy | Solar hot water (with gas condensating boiler top up) |
| Fuel strategy | Mains Gas. |
| Renewable energy strategy | Solar thermal |
| Passive Solar strategy | Solar thermal |
| Space cooling strategy | Natural ventilation - cross ventilation |
| Daylighting strategy | |
| Ventilation strategy | Mechanical heat recovery ventilation (winter) and natural ventilation (summer). |
| Airtightness strategy | Airtight details |
| Strategy for minimising thermal bridges | Continuity of insulation including exterior insulation, loft insulation and underfloor insulation of entire structural zone. |
| Modelling strategy | Heat 2 and Passivhaus Planning package (PHPP) |
| Insulation strategy | 300mm exterior and loft insulation. 150mm of insulation in suspended floor. |
| Other relevant retrofit strategies | |
| Contextual information |
Building services
| Occupancy | |
|---|---|
| Space heating | |
| Hot water | |
| Ventilation | |
| Controls | |
| Cooking | |
| Lighting | |
| Appliances | |
| Renewable energy generation system | |
| Strategy for minimising thermal bridges |
Building construction
| Storeys | |
|---|---|
| Volume | - |
| Thermal fabric area | - |
| Roof description | |
| Roof U-value | - |
| Walls description | |
| Walls U-value | - |
| Party walls description | |
| Party walls U-value | - |
| Floor description | |
| Floor U-value | - |
| Glazed doors description | |
| Glazed doors U-value | - - |
| Opaque doors description | |
| Opaque doors U-value | - - |
| Windows description | |
| Windows U-value | - - |
| Windows energy transmittance (G-value) | - |
| Windows light transmittance | - |
| Rooflights description | |
| Rooflights light transmittance | - |
| Rooflights U-value | - |