25-08-2017, 09:32 PM
BedZED
BedZED - Wikipedia, the free encyclopedia.pdf (Size: 1.04 MB / Downloads: 76)
Location
BedZED is accessible from the east side of London Road
(A237), opposite New Road, approximately 500 metres
north of Hackbridge station. Because of BedZED's lowenergy-
emission concept, cars are discouraged; the project
encourages public transport, cycling, and walking, and has
limited parking space.
The development is within about five minutes walk of
Hackbridge station, which services trains from London
Victoria and St Pancras International via London
Blackfriars. There is a Tramlink service from Croydon or
Wimbledon to Mitcham Junction station, which is within 15 minutes walk of BedZED.
Principles
Zero energy—The project is designed to use only
energy from renewable sources generated on site.
There are 777 m² of solar panels. Tree waste fuels
the development's cogeneration plant (downdraft
gasifier) to provide district heating and electricity.
The gasifier is not being used, because of technical
implementation problems, though the technology has
been and is being used successfully at other sites.
High quality—The apartments are finished to a high
standard to attract the urban professional.
Energy efficient—The houses face south to take
advantage of solar gain, are triple glazed, and have
high thermal insulation.
Water efficient—Most rain water falling on the site is
collected and reused. Appliances are chosen to be
water-efficient and use recycled water when
possible. A "Living Machine" system of recycling
waste water was installed, but is not operating.
Low-impact materials—Building materials were
selected from renewable or recycled sources within
35 miles of the site, to minimize the energy required
for transportation.
Problems
A review of the BedZed development in 2010[3] drew mainly positive conclusions. Residents and neighbours were
largely happy. However, a few significant failures were highlighted, for example:
the Biomass wood chip boiler was no longer in operation and the back up power source, a gas boiler, was
now used.[3]
the 'Living Machine' water recycling facility had been unable to clean the water sufficiently. The cost of the
facility also made it unviable.[3]
the passive heating from the sunspaces had been insufficient for comfort in winter and created overheating in
summer.[3]
plans to create allotments in an adjacent field had failed.[3]
despite best efforts, residents were on average still leaving an ecological footprint of 1.7 planets, which is
more than the target of 1.0 planet (but much less than the UK average of 3 planets).[3]
Embodied carbon
The greenhouse gases released as a result of building construction - the embodied carbon in buildings - is usually
ignored. But it was calculated for BedZED by one of the project initiators, BioRegional. They say:
the embodied environmental impacts of BedZED’s construction materials are within the same range as
standard UK housing. The total embodied CO2 of BedZED is 675kg/m2, whilst typical volume house
builders build to 600-800kg/m2.[4]
This means a 100m2 flat in BedZED has embodied carbon of 67.5 tonnes CO2. Compare this to carbon rations
suggested in the GreenRationBook [2] (http://www.greenrationbook.org.uk/) :
The average UK citizen creates 11 tonnes of carbon dioxide equivalent (CO2e) a year. New UK
targets aim to cut this by 80%. Dividing the ration equally between categories "consumables",
"building", "transport" and "government", allows 1.5kg per day.