A report on energy efficient design principles applied to Beddington zero (fossil) energy development at Beddington, Sutton
Beddington Zero Energy Development (BedZED) is a housing development designed by Bill Dunster Architects (now known as Zed Factory) in partnership with the Peabody Trust and the BioRegional Development Group. BedZED is the UK’s largest carbon-neutral housing development and was the first of its kind in the UK when completed in 2002. BedZED is a mixed-use, mixed-tenure development that incorporates many innovative approaches to energy conservation and environmental sustainability. For this review I am going to examine how the designers of BedZED have used various technologies and design principles in their pursuit of making BedZED a truly carbon neutral development. The areas I am going to look at are the building’s fabric and the materials used in its construction, how the building utilises passive solar design, and finally the HVAC and building systems utilized in the development.
Building Fabrics & Materials
Through the materials used in its construction and the design of its fabric, BedZED has tried to reduce its environmental impact in two ways. The first is by reducing its energy consumption and the second by reducing the embodied energy in the materials used to build the project. Despite being a zero carbon development, the first thing that struck me when visiting BedZED was that it didn’t look like an experimental piece of architecture. The houses were clearly different to a standard housing development, but they looked modern and contemporary rather than a laboratory for testing new products and principles, only the slight glimpse of a wind cowl on the roofs and the photovoltaics (PVs) scattered on the façade gives this impression as you walk around the site. Inside, the interiors are pleasant and only the deep reveals on the windows and the exposed soffit gives you a clue that this is not a standard housing development. BedZED works on the principle that if it can reduce the energy it consumes through hot water heating and space heating, the less energy it will have to produce to be a carbon neutral development. The building fabric is key in reducing the energy that is used in each of the dwellings and is dealt with in several ways. The most obvious way this is done is by ‘super insulating’ the buildings. BedZED houses have an additional 300mm of insulation than you would usually expect from a standard housing development, this takes the U-Value of the BedZED walls to an impressive 0.11 W/m2K compared with 0.45 W/m2K of a house built to 1995 Building Regulations . This extra insulation acts to keep out the cold from the outside but to also keep the internal heat gains from kitchens, occupants and electrical equipment inside the building. This has proven very successful and means that units require no central heating for large parts of the year, it is only when the weather is very cold that occupants have found that they need to use the heating system which is used as a back-up. This has allowed for an 88% reduction in space heating compared to the national average. This is not the only way that the fabric is used to control the internal environment of the units. The extra insulation is used as a ‘jacket’ to the rest of the structure. The buildings are constructed from thermally massive materials that store heat during warm conditions and release heat at cooler times. For this to work the insulation jacket has to sit on the outside of the construction so that the concrete soffits and thermal blocks can be left exposed. One criticism I have of this is that it restricts the options for the occupants on how they can decorate their unit which was apparent in the show flat we looked around. Some people may like an exposed soffit but others may like to apply a different finish to the ceiling which could upset the way in which the structure...