Cottage retrofit, Chale Green, Isle of Wight
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as PDF This project will focus on a dwelling typical for this area and will seek to establish a complementary and replicable set of measures which significantly reduce energy use and CO2 emissions associated with this particular type of property. The measures are intended to be carried out whilst the property remains unoccupied. It is intended that the findings will inform the remainder of SWHAs similar properties, and will also be widely applicable to other social landlords or building owners with similar stock, since there are around 7 million solid-walled properties in the UK.
Retrofit for the future ZA629H
Cottage retrofit, Chale Green, Isle of Wight : 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 | 24635 kWh/yr | 4053.56 kWh/yr | - |
|---|---|---|---|
| Natural gas use | - | - | - |
| Oil use | - | - | - |
| LPG use | - | - | - |
| Wood use | - | - | - |
| Other Fuel | - | - | - |
| Pre-development | Forecast | Measured | |
| Primary energy requirement | 710 kWh/m².yr | 117 kWh/m².yr | - |
|---|---|---|---|
| Annual CO₂ emissions | 168 kg CO₂/m².yr | 28 kg CO₂/m².yr | - |
| Annual space heat demand | - | 69.9 kWh/m².yr | - |
Renewable energy
| Electricity generation | Forecast | Measured |
|---|---|---|
| PV | 1765 kWh/yr | - |
| Other Renewables Tech | - | - |
| Electricity consumed by generation | - | - |
| Primary energy requirement offset by renewable generation | 66 kWh/m².yr | - |
| Annual CO₂ emissions offset by renewable generation | 16 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 | 23.7 W/m² demand |
Airtightness
| Date | Result | |
| Pre-development air permeability test | - | - |
|---|---|---|
| Final air permeability test | - | 3.17m³/m².hr @ 50 Pascals |
Project description
| Stage | Under construction |
|---|---|
| Start date | 01 March 2010 |
| Occupation date | 25 July 2010 |
| Location | Chale Green Isle of Wight England |
| Build type | Refurbishment |
| Building sector | Public Residential |
| Property type | Semi-Detached |
| Construction type | Solid Brick |
| Other construction type | |
| Party wall construction | Solid Brick |
| Floor area | 86.8 m² |
| Floor area calculation method | Treated Floor Area (PHPP) |
| Building certification |
Project Team
| Organisation | ECD Architects |
|---|---|
| Project lead person | Energy Conscious design, Studio 3, Blue lion Place 237 Long Lane, London SE1 4PU |
| Landlord or Client | Southern Housing Group, PO Box 643 Horsham, West Sussex RH12 1XJ |
| Architect | Energy Conscious design, Studio 3, Blue lion Place 237 Long Lane, London SE1 4PU |
| Mechanical & electrical consultant | Environmental Design Associates, 31 Wick Road, Teddington, Middlesex, TW11 9DN |
| Energy consultant | ECD Project Services, Studio 3, Blue lion Place 237 Long Lane, London SE1 4PU |
| Structural engineer | Carter Clack Partnership, 49 Romney Street, Westminster, London, SW1P 3RF |
| Quantity surveyor | The Keegans Group, Studio 2, 193-197 Long Lane, London, SE1 4PD |
| Consultant | Public Participation, Consultation and Research, Studio 2, 193-197 Long Lane, London, SE1 4PD |
| Contractor | TBC |
Design strategies
| Planned occupancy | Exisitng Tennants - Family |
|---|---|
| Space heating strategy | Heating will be provided by an Air source heat pump and new radiator system. Heat will be recovered from exhaust air via the use of mechanical ventilation with heat recovery unit. |
| Water heating strategy | Hot water will be provided by high efficiency flat plate solar collectors and large capacity thermal store with an air source heat pump as a backup. |
| Fuel strategy | Electricity |
| Renewable energy strategy | Onsite electric production by 2.52 kWp photovoltaic panels and heat production by solar thermal collectors. |
| Passive Solar strategy | Window fenestration has been simplified in proposed replacement windows to maximise solar gain. |
| Space cooling strategy | HRV with summer bypass combined with natural ventilation for summer period. Night purging during heat waves. |
| Daylighting strategy | Window fenestration has been simplified in proposed replacement windows to maximise day light. |
| Ventilation strategy | Heat recovery ventilation and additional natural ventilation by opening windows during summer months as required.. |
| Airtightness strategy | All existing vents and chimneys blocked up. New air barrier created by OSB board at ceiling level with taped joints and perimeters taped to masonry walls and plastered over. Service void created bellow this to eliminated penetrations. Windows, floors, junctions and all penetrations sealed with proprietary air tight tapes, membranes and grommets. All voids such as cavities filled to mitigate thermal bypass. |
| Strategy for minimising thermal bridges | Continuous insulation maintained throughout. Geometric thermal bridges minimised. Junctions assessed include: Ground floor junction, external corner, party wall, party roof, party floor, eaves, verge, window jamb, head and sill, door jamb, head and threshold. |
| Modelling strategy | Whole house modeling was undertaken in both PHPP and SAP, with the use of extension sheets for both. The results provided for existing energy usage were calculated in SAP, as this software is more suitable for modeling poor performing buildings. The proposed results were modeled in PHPP as this software is more accurate for predicating energy usage in high performing buildings. |
| Insulation strategy | - The solid ground floor slab will be left un-insulated to minimise tenant disruption. - The existing walls will be clad externally with an insulated render system to give a U-value of 0.15 w/m2K. - The existing windows will be replaced with high perf |
| Other relevant retrofit strategies | We propose to fit an intelligent heating controller designed to save energy and improve comfort in residential buildings. The system controls both central and water heating, reducing energy consumption by automatically monitoring and learning occupant behavior and preferences. It also provides an easy to use and simply user interface as well as covering all energy monitoring requirements. |
| Contextual information | South Wight Housing Association (SWHA) is a wholly owned subsidary of Southern Housing Group following the merger of the two organisations in July 2002. In October 2005, they became the largest housing association on the Isle of Wight following their merger with the Isle of Wight Housing Association. They own and manages over 3000 homes and with the help of nearly 300 staff, provide over one-third of the Isle of Wight supported housing. Many of this stock, particularly to the west of the island, is not connected to mains gas and is constructed from solid brick walls, presenting particular issues with regard to fuel poverty. |
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 |