Beddington Zero Energy Development (BedZED) - the Environment Centre (tEC)

BedZed

Credit: BioRegional


The Beddington Zero (Fossil) Energy Development (BedZED) was the UK’s largest low carbon community. BedZED is a mixed-use, mixed-tenure development that incorporates innovative approaches to energy conservation and environmental sustainability. In fact, BedZED was designed to minimize its ecological impact both in construction and in use. This project was completed in March 2002 and has won many awards.

Challenges Encountered
There have been some problems with the Combined Heat and Power (CHP) plant and the project is now back on the grid using non-renewableelectricity. The CHP has recently been removed to make way for a biomass boiler. It is hoped that the remaining electricity demand will be met through a green tariff.

Passive Measures
Consideration was given to the environmental impact of the construction process and materials used, the sourcing of reclaimed and recycled materials, and a local sourcing policy to reduce haulage carbon emissions. For example reused structural steel was used in the workspace framing structure, and reclaimed timber for internal partition studwork. Moreover, BedZED is constructed from renewable materials such as wood certified by the Forest Stewardship Council which lessens the burden on the environment by the development.

One of the designer’s ideas was to recommend distinctly different orientations for the varying building uses of homes and workspaces. Workspaces have potentially high occupancy levels and office machine heat gains which, added to solar gain, can at times give too high a room temperature and prompt a need for summer supplementary mechanical cooling. Homes, on the other hand, have less occupancy density and less internal heat gains, so by facing south, gain useful benefit from supplementary solar heat gain. Actually, the thermal inertia coupled with using passive cooling plus cool night ventilation also keep summer room temperatures low. Triple glazing and super insulation was also used in order to save energy.

Mechanical ventilation has been successfully replaced by natural ventilation systems. Then, only renewable energy is used to ventilate the rooms.

The cowls, which are located on the roofs of the buildings, are a result of 10 years of research by Arup into the capture of low-velocity wind energy. The wind cowl system was developed to deliver pre-heated fresh air to each home and extract its vitiated air, complete with heat recovery from the extracted ventilation air. This allowed the cowl to achieve a certifiable ventilation and heat recovery performance, and hence the omission of all ventilation fans, trickle vents, electrics, controls, and fresh air heating in the homes, thus providing a system using only renewable energy.

Technologies Employed
Until 2005 the site was powered by a bio-fuelled combined heat and power (CHP) system. To make bio-fuelled CHP viable the challenge was to roughly halve the building’s energy demand, so reducing the plant size needed. The elimination of fans and pumps, and the use of EU ‘A’ rated domestic appliances, low-energy compact fluorescent luminaries, and meters visible to the consumers, were all aspects of reducing electrical energy demand. The combined heat and power plant (CHP) was an energy cogeneration type power generator. The CHP plant generated electricity like any normal power plant, but in addition the CHP unit harnessed the heat energy generated by the primary fuel conversion to electricity. The heat energy was captured in hot water and distributed to the community through a system of super insulated pipes. The primary fuel for the CHP was wood chips from tree surgery waste that would otherwise be sent to the landfill.

However there were some problems with CHP – the system was a prototype designed by a small company. The company went out of business before it could solve the technical issues. Had more resources been available to perfect the technology, in time it could have operated to projected standards. In an evolution of the energy strategy, the CHP has recently been removed to make way for a biomass boiler, run on local waste wood, which should be installed in 2011.

777m2 of photovoltaic panels provide around 29%of the site’s needs. They were originally intended to provide enough power for 40 electric cars. Hoewever, since the electric car market is yet to take off in the UK, the electricity has been used on site for general purposes. It is planned for the rest of the site’s electricity needs to be met by a green tariff.

To minimize the use of potable water the following water-saving technologies have been used:
  • Flow restrictors
  • Mains pressure showers
  • Visible meters for consumers
  • EU ‘A’ grade water-consuming appliances
  • Low/dual flush toilets
  • Rainwater storage tanks (for irrigation and toilet flushing)
The aim of the project was to reduce treated potable water demand by more than 50% and then treat the effluent on site - with less resources being used and the water available for recycling.

The use of a reed-water infiltration system that purifies blackwater into greywater for use in non-potable applications is one innovation of BedZED. It means that vegetation is used as a cleaning agent in the secondary and tertiary treatment stages (partly because of its low energy consumption).

Awards and Achievements
  • Civic Trust Sustainability Award 2004 - Winner
  • Housing Design Awards 2003: Completed Scheme Award - Winner
  • RIBA Journal Sustainability Award 2003 - Winner
  • Stirling Prize 2003 - Finalist
  • Finalist for the World Habitat Awards 2002 - Finalist
  • Building Energy Globe Award 2002 - Winner
  • Building Services Award for Innovation 2002 - Winner
  • UK Solar Awards 2001 - Winner
  • Housing Design Award for Sustainability 2001 - Winner
  • Office of the Deputy Prime Minister’s (ODPM) Award for Sustainable Communities 2003 - Finalist
Page last updated 15th September 2010
The content of this website reflects the author’s views. the Environment Centre (tEC) and the INTERREG IVA 2 Mers Seas Zeeën Cross-border Cooperation Programme Authorities accept no liability for the accuracy of the claims made and any use that may be made of the information contained therein.