The Oxford Whole House Carbon Reduction Project
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as PDF Low energy and low carbon retrofit of a typical 19th century end terrace house to achieve carbon emission reductions above 80%.This reduction is achieved by following a whole house approach and prioritising low energy demand through fabric improvements first, followed by tried and tested low/zero carbon systems to achieve an estimated 85% reduction in carbon emissions as compared to the existing house. The methodology has incorporated a user centred approach and has been informed by a thorough, pre-retrofit monitoring and feedback survey for the selection of appropriate strategies.
Retrofit for the future ZA398Y
The Oxford Whole House Carbon Reduction Project : 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 | 802 kWh/yr | 1272.35 kWh/yr | 1879 kWh/yr |
|---|---|---|---|
| Natural gas use | 24138 kWh/yr | 3375.6 kWh/yr | 3957 kWh/yr |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 387 kWh/m².yr | 92 kWh/m².yr | 120 kWh/m².yr |
|---|---|---|---|
| Annual CO₂ emissions | 71 kg CO₂/m².yr | 19 kg CO₂/m².yr | 25 kg CO₂/m².yr |
| Annual space heat demand | - | 19.88 kWh/m².yr | - |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| 1kWp Photovoltaic Panel Array | 797.5999756 kWh/yr | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | 66 kWh/m².yr | 120 kWh/m².yr |
| Annual CO₂ emissions offset by renewable generation | 13 kg CO₂/m².yr | 25 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 | - | 5.86m³/m².hr @ 50 Pascals |
|---|---|---|
| Final air permeability test | - | 4.04m³/m².hr @ 50 Pascals |
Project description
| Stage | Under construction |
|---|---|
| Start date | 02 August 2010 |
| Occupation date | 10 December 2010 |
| Location | Oxford Oxfordshire England |
| Build type | Refurbishment |
| Building sector | Public Residential |
| Property type | End Terrace |
| Construction type | Solid Brick |
| Other construction type | 230 mm Solid brick |
| Party wall construction | Solid Brick |
| Floor area | 76.9 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |
Project Team
| Organisation | Ridge and Partners LLP |
|---|---|
| Project lead person | Ridge and Partners LLP |
| Landlord or Client | Oxford City Council |
| Architect | Ridge and Partners LLP |
| Mechanical & electrical consultant | Ridge and Partners LLP |
| Energy consultant | Oxford Brookes University OISD |
| Structural engineer | Ridge and Partners LLP |
| Quantity surveyor | Ridge and Partners LLP |
| Consultant | |
| Contractor |
Design strategies
| Planned occupancy | 2 occupants, one of whom spends most of the weekdays and weekend days in the house. |
|---|---|
| Space heating strategy | Heating from mains gas. High efficiency condensing boiler feeding radiators. |
| Water heating strategy | Solar hot water (with high efficiency condensing boiler back up). |
| Fuel strategy | Mains gas, mains electricity |
| Renewable energy strategy | South-east oriented 1 kWp photovoltaic panel array to be installed onto the existing roof. |
| Passive Solar strategy | Solar gains from south-west side windows. |
| Space cooling strategy | Natural ventilation for most of the cooling season. Daytime use of MVHR with night purging during heat waves. |
| Daylighting strategy | Four rooflights have been added at the rear (north east) of the house, to improve the daylight levels in the house. 2 rooflights out of these are in the kitchen. Living areas (south west) and master bedroom (south west) achieve minimum average daylight factor of 2%. |
| Ventilation strategy | Mechanical ventilation with heat recovery (winter). Openable windows (summer) |
| Airtightness strategy | Air - permeability of 1m3/hm2 @ 50 Pa is targeted, combined with a mechanical ventilation system with heat recovery. Upgradation of windows and doors, minimising thermal bridges and insulating and sealing all air leakage pathways identified in the air pressure test will ensure an airtight fabric is achieved. |
| Strategy for minimising thermal bridges | Using accredited construction details, by detailing for continuous insulation and air barrier on external walls to prevent condensation. Party wall insulation to minimise the thermal bridge between the party wall (back and front) and external wall, and to reduce heat losses to the neighbouring property. All internal walls to be lined with 25mm continuous insulation to reduce heat loss into the footings. |
| Modelling strategy | SAP 2005 was used as the primary modelling tool. All SAP calculations were carried out in the approved SAP 2005 software SAPCalc. A PHPP analysis was also carried out for verifying the final package of measures. |
| Insulation strategy | External solid brick wall U-Value of 0.24W/m2K (internal insulation Kingspan Kooltherm K18 insulating boards), Rear extension, Cavity wall U-Value=0.1W/m2K, (75mm cavity fill and 200mm phenolic foam), Existing Pitched roof U-value=0.1W/m2K, (250mm of polyurethane), Existing flat roofs to be replaced with new pitched roofs, U-value=0.1W/m2K, Concrete ground floor U-value of 0.2W/m2K, (vacuum insulation panels) |
| Other relevant retrofit strategies | |
| Contextual information | The house is in an area of historical value and it is highly unlikely that changes to the external appearance of the house would be permitted. The solid brick walls have been insulated internally and all window sizes have been retained. |
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 | |
|---|---|
| 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 |