Clapham Townhouse Retrofit
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as PDF A complete refurbishment and retrofit of a Victorian cottage. This end of terrace house was extended and retrofitted to provide an exemplar development in energy efficiency and a test bed for various types of renewable technologies. Key to the sucess was a strategy of creating a thermally efficient and air tight building, coupled with an MVHR system to control ventilation and internal humidity.
Clapham Townhouse 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 | - | - | 6051 kWh/yr |
|---|---|---|---|
| Natural gas use | - | - | 13 kWh/yr |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| mains gas | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | - | - | 84 kWh/m².yr |
|---|---|---|---|
| Annual CO₂ emissions | - | - | 20 kg CO₂/m².yr |
| Annual space heat demand | 290 kWh/m².yr | 200 kWh/m².yr | 78.58 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 | - | 84 kWh/m².yr |
| Annual CO₂ emissions offset by renewable generation | - | 20 kg CO₂/m².yr |
Calculation and targets
| Whole house energy calculation method | SAP |
|---|---|
| Other whole house calculation method | - |
| Energy target | Retrofit for the Future |
| Other energy targets | - |
| Forecast heating load | - |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | 02 July 2013 | 3.54m³/m².hr @ 50 Pascals |
Project description
| Stage | Occupied |
|---|---|
| Start date | 08 March 2011 |
| Occupation date | 23 June 2013 |
| Location | London London England |
| Build type | Mixed |
| Building sector | Private Residential |
| Property type | End Terrace |
| Construction type | Solid Brick |
| Other construction type | |
| Party wall construction | |
| Floor area | 180 m² |
| Floor area calculation method | Actual Floor Area (SAP) |
| Building certification |
Project Team
| Organisation | Granit |
|---|---|
| Project lead person | James Munro |
| Landlord or Client | Robert Wilson |
| Architect | James Munro |
| Mechanical & electrical consultant | Granit |
| Energy consultant | Responsible Energy Management (REM) |
| Structural engineer | Mitchinson Macken |
| Quantity surveyor | N/A |
| Consultant | |
| Contractor | Best Place 4u Ltd |
Design strategies
| Planned occupancy | Designed for a family of 4. |
|---|---|
| Space heating strategy | Underfloor heating through out linked to solar thermal store and integrated gas boiler back up. |
| Water heating strategy | Solar thermal store connected to solar panels on south-west facing roof and integrated gas boiler back up. |
| Fuel strategy | Mains gas. Mains electricity. |
| Renewable energy strategy | N/A |
| Passive Solar strategy | N/A |
| Space cooling strategy | Majority of glazing to North and North East Elevations to reduce solar gain and over heating potential. Large thermal mass and |
| Daylighting strategy | Large expanse of glazing to rear of main house and rear/side extension. rooflight above internal shower room. |
| Ventilation strategy | Whole house mechanical extract ventilation. |
| Airtightness strategy | All penetrations on the fabric sealed. All plaster boards taped and sealed before skimming. |
| Strategy for minimising thermal bridges | 2m overlap of internal and external insulation at junctions. |
| Modelling strategy | Sun path modelling used in Archicad to establish potential for overheating and solar heating. |
| Insulation strategy | Application of EWI to all new solid and existing flank walls, IWI used on front elevation where historic details could not be altered. Warm roof construction to new roofs. |
| Other relevant retrofit strategies | |
| Contextual information | Property is in a conservation area. |
Building services
| Occupancy | Single occupier and dog, plus guests |
|---|---|
| Space heating | Underfloor heating |
| Hot water | A gas condensing boiler, combined with a thermal store known as a GasSolarUnit combination (supplied by Rotex / RER) is topped up from solar panels fitted to the South facing front roof. |
| Ventilation | A high level of air tightness was targeted duringthe design and construction phases, to ensure the e ectivness of the MVHR system supplied by Air ow Ltd. All vents including trickle vents were omitted from the external fabric, and openings (i.e. windows a nd doors) were specifed with air tightness in mind |
| Controls | |
| Cooking | Induction hob and oven |
| Lighting | 100% low energy LED lighting |
| Appliances | |
| Renewable energy generation system | A gas condensing boiler, combined with a thermal store known as a GasSolarUnit combination (supplied by Rotex / RER) is topped up from solar panels fitted to the South facing front roof. This provides all of the space heating and hot water demand for the house. Under oor heating was used on all oors, with timber or tiled oors to ensure thermal e ciency and comfort. |
| Strategy for minimising thermal bridges |
Building construction
| Storeys | 3 |
|---|---|
| Volume | 450m³ |
| Thermal fabric area | 235 m² |
| Roof description | The 2 roofs were highly insulated. New pitched roof consisting of eternit tiles with 150mm Celotex XR4000 between joists and 25mm Celotex PL4000 below joists. U value of 0.12 W/MsqKNew at roof constructed of Green roof system on GRP, on 126mm Celotex TD4000. U value of 0.16 W/ MsqK |
| Roof U-value | 0.12 W/m² K |
| Walls description | The front elevation was left intact on the 2 lower oors, with a new front wall built in solid wall construction above. All existing solid brick walls were insulated internally with 60mm Celotex PL4000, built o battens to create 30mm void. Then 12.5mm taped plasterboard. U Value of 0.29 0W/MsqKAll new walls were built in solid blockwork and insulated externally with 70mm Phenolic Weber Therm XP External wall insulation system. U value of 0.29 W/MsqK |
| Walls U-value | 0.29 W/m² K |
| Party walls description | insulated externally with 70mm Phenolic Weber Therm XP External wall insulation system |
| Party walls U-value | 0.30 W/m² K |
| Floor description | Ground oor was 100% renewed with 75mm Celotex FF4075 insulation under new 120mm concrete slabs. U Value of 0.21 W/MsqK |
| Floor U-value | 0.21 W/m² K |
| Glazed doors description | New casement and feature glazing,Thermally broken Aluminium framed system with Triple glazing (Lumax system) U value of 1.9 W/MsqK |
| Glazed doors U-value | 1.90 W/m² K installed |
| Opaque doors description | |
| Opaque doors U-value | - uninstalled |
| Windows description | New sash windows, double glazed 24mm SoftCoast Argon heat film achieving an overall U value of 1.8W/MsqK |
| Windows U-value | 1.80 W/m² K installed |
| Windows energy transmittance (G-value) | - |
| Windows light transmittance | - |
| Rooflights description | |
| Rooflights light transmittance | - |
| Rooflights U-value | 2.20 W/m² K |