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Midsummer Housing Association used the predecessor to the BREEAM Environmental Standard as a bench mark. The construction is a solid brick wall to which has been applied 150mm mineral wool insulation. This gives a wall U value of 0.2. The building is then clad with boarding and render to mask and protect the insulation. The dwellings have gas condensing boilers, triple glazed windows and low energy lighting throughout. In four of the five units ventilation is achieved by means of mechanical extracts and trickle vents. In the bungalow, however, there is an experimental heat exchange system through a double network of earth tubes within the structure of the building. Using the warmth from the used internal air, the incoming air is pre-heated. Also in line with the BREEAM Environmental Standard all the basic materials are from sustainable sources, have low embodied energy and contain no CFCs, HCFCs or volatile organic pollutants where possible. Entrance lobbies which help to draught-proof the main entrances to the dwellings contain separate compartments to allow sorting of refuse for recycling. With regards to water consumption all five dwellings have low usage equipment and water butts for rainwater collection. Landscaping is also designed with low run-off characteristics. As well as incorporating energy efficiency measures, the design has been prepared with a view to producing an approach to construction which does not require highly skilled labour. In order to meet the requirements of flexibility and use to meet the changing needs of residents, none of the internal walls are load bearing and therefore internal layouts are adaptable. The units have also been designed with the ability to accommodate hoists and lifts that may be required for disabled or elderly occupiers. The total cost for the scheme is around 9% higher than for an equivalent standard development with no special features. It is, however, within the cost limits currently applied to social housing by the Housing Corporation (TCI). Although the overall cost is around 9% higher, the return for that extra outlay by the Association results in considerable savings on utility bills for residents. An important lesson to learn from a project like this is that even though in theory statistics such as fuel consumption and energy efficiency look impressive, in real life it is difficult to assess monitoring data because of the varying lifestyles of occupants.
Contact:
Rachel Jones,
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