Gentoo Retrofit Bid 3
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as PDF Refurbishment of a pair of semi-detached non-traditional construction semi detached houses using PassivHaus techniques.
Retrofit for the future ZA532L
No images have been supplied for this project
Energy and fuel use
Measured data from renewable generation is not yet available.
Fuel use
| Pre-development | Forecast | Measured | |
| Electricity use | 1812 kWh/yr | 1053 kWh/yr | - |
|---|---|---|---|
| Natural gas use | 28659 kWh/yr | 3936 kWh/yr | - |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 586 kWh/m².yr | 112 kWh/m².yr | - |
|---|---|---|---|
| Annual CO₂ emissions | 109 kg CO₂/m².yr | 22 kg CO₂/m².yr | - |
| Annual space heat demand | - | 47 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 | 112 kWh/m².yr | - |
| Annual CO₂ emissions offset by renewable generation | 22 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 | 17 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | - | - |
Project description
| Stage | Under construction |
|---|---|
| Start date | 05 April 2010 |
| Occupation date | 18 May 2010 |
| Location | Sunderland Tyne & Wear England |
| Build type | Refurbishment |
| Building sector | Public Residential |
| Property type | Semi-Detached |
| Construction type | Other |
| Other construction type | Laing Easi-form Construction: 2 leaves of reinforced concrete |
| Party wall construction | cavity wall |
| Floor area | 64 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |
Project Team
| Organisation | Gentoo Sunderland Ltd |
|---|---|
| Project lead person | Devereux Architects |
| Landlord or Client | Gentoo Sunderland |
| Architect | Devereux Architects |
| Mechanical & electrical consultant | Alan Clarke (Mech) & Gentoo Construction (Elec) |
| Energy consultant | Alan Clarke (Mech) |
| Structural engineer | Gentoo Construction |
| Quantity surveyor | Gentoo Construction |
| Consultant | |
| Contractor | Gentoo Construction |
Design strategies
| Planned occupancy | As at present: |
|---|---|
| Space heating strategy | Gas condensing boiler to use existing radiator central heating system. Room compensated boiler flow temperature control. A-rated low energy circulation pump. |
| Water heating strategy | Solar thermal using roof-integrated flat panels, twin coil cylinder with 100mm insulation located in warm loft. Gas boiler back up, no immersion heater. |
| Fuel strategy | Existing supplies: mains gas and electricity |
| Renewable energy strategy | None |
| Passive Solar strategy | Retaining existing opening sizes. Full glazing to south facing kitchen door. |
| Space cooling strategy | Thanks to modest glazed areas PHPP shows that natural ventilation will be sufficient. Thermal mass retained inside the building will aid night cooling if required. |
| Daylighting strategy | Existing window openings used, with increased glass area and double glazing rather than triple. |
| Ventilation strategy | Winter ventilation using mechanical heat recovery ventilation. Automatic relative humidity control. MVHR unit located in kitchen for ease of access for maintenance. Opening windows for use in summer. |
| Airtightness strategy | Roof air barrier membrane sealed to parge coat of render on masonry wall. Windows taped to wall and gaps filled with flexible expanding foam. Solid ground floor. Rubber seals around pipe, flue and cable penetrations (eg pro clima grummet). Party wall enclosed by treatment of both semidetached houses together. |
| Strategy for minimising thermal bridges | Thermal bridge free approach: roof insulation over rafters to enable full thickness to go over eaves and gable and join external wall insulation. Windows fixed to external surface of wall so within the external insulation layer. Wall insulation extends below ground (without base rail) down to foundations to minimise floor heat loss. This has been modelled using Therm to check internal temperatures and heat loss. |
| Modelling strategy | PHPP (whole house energy and overheating) Therm for thermal bridging |
| Insulation strategy | External "overcoat": Over rafters to raise roof, using glass fibre, U=0.11 External wall insulation using graphite EPS, U=0.13 Narrow access between houses means insulation thickness is reduced on gables to U=0.21 No floor insulation as tenants remain in-situ. Insulation provided by carpet and underlay, and by below-ground wall insulation. Windows use highly insulating PVC frame (U=0.8) and high performance double glazing (U=1.1) with stainless spacers. |
| Other relevant retrofit strategies | Tenants remain in the houses throughout. Two semi detached houses are retrofitted together to eliminate problems at party wall and enable removal of chimney. |
| Contextual information | Treating two houses together has limited the budget and forced a focus on cost-effective measures. External walls are currently rendered so external appearance not changed greatly by external insulation system. |
Building services
| Occupancy | NULL |
|---|---|
| Space heating | NULL |
| Hot water | NULL |
| Ventilation | NULL |
| Controls | NULL |
| Cooking | NULL |
| Lighting | NULL |
| Appliances | NULL |
| Renewable energy generation system | NULL |
| Strategy for minimising thermal bridges | NULL |
Building construction
| Storeys | 0 |
|---|---|
| Volume | - |
| Thermal fabric area | - |
| Roof description | NULL |
| Roof U-value | 0.00 W/m² K |
| Walls description | NULL |
| Walls U-value | 0.00 W/m² K |
| Party walls description | NULL |
| Party walls U-value | 0.00 W/m² K |
| Floor description | NULL |
| Floor U-value | 0.00 W/m² K |
| Glazed doors description | NULL |
| Glazed doors U-value | 0.00 W/m² K - |
| Opaque doors description | NULL |
| Opaque doors U-value | 0.00 W/m² K - |
| Windows description | NULL |
| Windows U-value | 0.00 W/m² K - |
| Windows energy transmittance (G-value) | - |
| Windows light transmittance | - |
| Rooflights description | NULL |
| Rooflights light transmittance | - |
| Rooflights U-value | 0.00 W/m² K |