Sustainable Cities™

Sutton: BedZED - Leading the way in eco village design

The eco-village of BedZED was initially developed with the ambition of becoming carbon neutral. Seven years after its completion, studies have revealed that BedZED's basic formal and material designs have vastly helped in working towards this goal while its many green technologies seem to have been less effective.

Sydvendte boliger i BedZED. Foto: Marcus Lyon. Flickr Creative Commons.

If everyone in the world lived like the average North American, we would need five planets-worth of resources to subsist. Three planets would suffice if everyone lived like the average European but this is still a sure shot away from the one planet that we inhabit. It is with this knowledge that the environmental organisation BioRegional has formulated the ambition of OnePlanetLiving and has attempted to demonstrate how such a lifestyle is possible in projects such as BedZED. Developed in cooperation with The Peabody Trust and Bill Dunster Architects, BedZED is a residential area south of London that  is located on an original brownfield site that used to be a sewage plant.  The development project was initiated with the goal of producing as much energy from renewable resources as it consumes. However, according to the architects behind BedZED's creation, we can never produce enough green energy to cover the current global level of consumption. It is therefore necessary to not only increase green energy production but also to dramatically limit the consumption of that energy.

BedZED is the result of holistic planning. Every detail of the development is designed to make it easier to lead a sustainable lifestyle than it is lead an unsustainable one. Elsewhere on this website we describe the green transport plan and the lifestyle-oriented approach that BedZED takes, which ensures that residents are involved and are contributing to the project's sustainability. However, the basic design of BedZED's infrastructure and the methods used in its construction are also key factors that make the development as sustainable as it is. All of BedZED's homes are fitted with low-energy lighting and appliances, have roof lights, and have several windows that face south, which allow the dwellings to maximize their intake of sunlight. Additionally, each housing unit has a conservatory: a large glass area towards the top of the structure that provides natural heating by retaining thermal solar energy. The dwellings are also heavily insulated so that they can retain the heat produced from kitchens and bathrooms and use it to bring the entire unit to a good level of thermal comfort. Furthermore, solar cells and wind turbines provide electrical and thermal energy and add to the long list of technologies that BedZED uses, including water-saving devices and rain collectors.

You don't need to be a sustainable idealist or fanatic to live at BedZED since much of the initial design ensures you that you live sustainably just by being there. According to Bill Dunster, you can even be an 'eco-sloth' and still achieve significant carbon savings.

"...there's already a big difference between the environmental impact of the eco-sloth in our BedZED and the environmental impact of a typical UK family in traditional housing. Our eco-sloth is already down to two-planet living" - Bill Dunster, 2005.

In 2007, studies showed that the electricity consumption of the average BedZED citizen was 45% less than that of the other residents of Sutton County.  The heat consumption was 81% lower and the use of water was reduced by 50%. Also, it is important to note that BedZED had produced much of the heat and electricity it used from wind turbines, solar panels and biomass burners. However, it seems that advanced technologies like these caused the most problems in terms of lessening BedZED's carbon footprint and the biomass burner resulted in especially large problems. The development originally had its own combined heat and power plant (CHP) and, after a promising start, the efficiency of this advanced technology started gradually declining, resulting in a shift from 80% of BedZED's energy produced from renewable sources in 2003 to 11% in 2006. A similar problem occurred with the development's "Living Machine", an innovative water treatment system that filters wastewater for use in toilets and irrigation. In combination with rainwater collection, it was estimated that the system could save each resident 15 litres of water every day but, since 2005, the Living Machine has been out of service due to lack of maintenance.

In spite of this, BedZED continues to excel in low energy consumption. Although the development has not yet managed to produce enough renewable energy to sustain local consumption and a global BedZED would still require two planets, it still illustrates that carbon emissions can be drastically reduced if simple attention is paid to formal and material design.

CHP (Combined Heat and Power Plant)

A CHP is a not exactly a common sight in Britain and, traditionally, such facilities were more prevalent in colder regions of the world such as Scandinavia. The advantage that a CHP has over an ordinary power plant is that, after material is burned to generate electricity, the heat that is given off is retained for use elsewhere (as in heating buildings). BedZED's plant is specifically fuelled by woodchips - a theoretically carbon-neutral energy source since the CO2 emissions from the burning are cancelled out by the fact that the tree supplying the wood absorbed CO2 in its lifetime. Despite the novelty of this system, technical problems have forced BedZED to draw much more of its energy from the public electricity supply.

The main problem, according to Dunster, is that the authorities did not want to be responsible for maintenance. In 2003, BedZED covered 80% of its energy through its "local" production, which includes wind power, solar cells and the CHP unit. As of late 2005, though, the CHP has been deficient and, in 2006, only 11% of local energy consumption was covered by renewable sources.

Living Machine

The Living Machine is a biological system for wastewater treatment that mimics the water purifying functions of wetlands. A number of living creatures ranging from plants, bacteria, algae and plankton to snails, clams and fish are included in an artificial ecosystem that accepts and processes sewage.  With each organism adhering to its own specific cleansing function, the system can filter the sewage to produce water that is useable in toilets and irrigation as well as plants that can be harvested for compost.

Like the CHP, the Living Machine requires constant maintenance and, since the system was not properly budgeted in BedZED, it has been inoperative since 2005. Due to BedZED's low water consumption, it was not possible to agree on a contract with the management of water supplier, Thames Water. According to Thames, such an agreement requires a minimum use of 50,000 cubic meters water per year and consumption at BedZED is usually around 6,000 cubic meters. Ultimately, it turned out that the Living Machine's energy consumption for pumping and aeration was unsustainable at such a relatively small scale such as that of BedZED. In fact, when consumption is not higher, it is both more economically and environmentally sustainable to connect to a central water supply. 

Last updated Tuesday, January 21, 2014