April 10, 2008

Buildings- Zero Energy Developments

The Beddington Zero Energy Development (BedZED) is the UK's largest carbon-neutral eco-community - the first of its kind in this country. BedZED was developed by the Peabody Trust in partnership with Bill Dunster Architects and BioRegional Development Group, environmental consultants.

The BedZED design concept was driven by the desire to create a net 'zero fossil energy development', one that will produce at least as much energy from renewable sources as it consumes. Only energy from renewable sources is used to meet the energy needs of the development. BedZED is therefore a carbon neutral development - resulting in no net addition of carbon dioxide to the atmosphere.

What are the features of BedZED?
The design is to a very high standard and is used to enhance the environmental dimensions, with strong emphasis on roof gardens, sunlight, solar energy, reduction of energy consumption and waste water recycling.

BedZED provides 82 residential homes with a mixture of tenures, 34 for outright sale, 23 for shared ownership, 10 for key workers and 15 at affordable rent for social housing - with a further 14 galleried apartments for outright sale.

The homes are a mixture of sizes and the project also includes buildings for commercial use, an exhibition centre, a children's nursery and a show flat so that visitors may see what it is like to live at BedZED.

The buildings
Buildings are constructed from thermally massive materials that store heat during warm conditions and release heat at cooler times. In addition, all buildings are enclosed in a 300mm insulation jacket.

BedZED houses are arranged in south facing terraces to maximize heat gain from the sun, known as passive solar gain. Each terrace is backed by north facing offices, where minimal solar gain reduces the tendency to overheat and the need for energy hungry air conditioning.

BedZED's architecture
BedZED has been designed to address environmental, social and economic needs. It brings together a number of proven methods - none of them particularly high tech - of reducing energy, water and car use. Crucially, it produces affordable, attractive and environmentally responsible housing and workspace.

Key features include:

Using renewable materials
Where possible, BedZED is built from natural, recycled or reclaimed materials. All the wood used has been approved by the Forest Stewardship Council or comparable internationally recognised environmental organisations, to ensure that it comes from a sustainable source.

Space heating
Through the innovative design and construction, heat from the sun and heat generated by occupants and every day activities such as cooking is sufficient to heat BedZED homes to a comfortable temperature. The need for space heating, which accounts for a significant part of the energy demand in conventional buildings, is therefore reduced or completely eliminated.

BedZED homes and offices are fitted with low energy lighting and energy efficient appliances to reduce electricity requirements.

To enable residents and workers to keep track of their heat and electricity use, meters are mounted in each home and office kitchen.

Combined heat and power plant
BedZED receives power from a small-scale combined heat and power plant (CHP). In conventional energy generation, the heat that is produced as a by-product of generating electricity is lost. With CHP technology, this heat can be harnessed and put to use.

At BedZED, the heat from the CHP provides hot water, which is distributed around the site via a district heating system of super-insulated pipes. Should residents or workers require a heating boost, each home or office has a domestic hot water tank that doubles as a radiator.

The CHP plant at BedZED is powered by off-cuts from tree surgery waste that would otherwise go to landfill. Wood is a carbon neutral fuel because the CO2 released when the wood is burned is equal to that absorbed by the tree as it grew.

Green transport plan
Transport energy accounts for a large proportion of the energy consumption of any development.

A green transport plan promotes walking, cycling and use of public transport. A car pool for residents has been established, and all these initiatives have helped to provide a strategic and integrated approach to transport issues.

The BedZED project shows that it is possible to reduce reliance on cars and introduced the first legally binding Green Transport Plan as a condition of planning permission.

BedZED's target is a 50% reduction in fossil-fuel consumption by private car use over the next ten years compared with a conventional development.

BedZED has been designed to encourage alternatives to car use.

Reducing 'embodied' energy
Embodied energy is a measure of the energy required to manufacture a product. A product that requires large amounts of energy to obtain and process the necessary raw materials, or a product that is transported long distances during processing or to market, will have a high-embodied energy level.

To reduce the embodied energy of BedZED, construction materials were selected for their low embodied energy and sourced within a 35-mile radius of the site where possible. The energy expended in transporting materials to the site was therefore minimised.

Education and employment
BedZED has become an excellent learning centre for sustainable development, attracting considerable local, national and international media coverage and interest.

The project also demonstrates imaginative ways of creating employment and funding the provision of affordable homes, with grants from the Housing Corporation supporting the development of the homes for shared ownership. Peabody also worked hard with Sutton Council to ensure that the properties available for shared ownership were as affordable as possible.




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