Lentis/BedZED

Beddington Zero Energy Development (BedZED) is a sustainable housing development in Hackbridge, London Borough of Sutton. It was designed to be the first large-scale “carbon neutral” community, creating zero carbon dioxide emissions.[7]

Introduction
BedZED was designed by Bill Dunster, in collaboration with Bioregional, to create the first large-scale, zero fossil-fuel eco-village. The London Borough of Sutton sold an undeveloped plot of land to the developers below market value, on the basis that the project would create greater community benefits than a conventional housing development, including reducing climate-changing emissions. The goal of this development was to limit individual resource consumption, while maintaining a comfortable and appealing lifestyle. Its vision was inspired by ideas like sustainable development and spaceman economy. This case study investigates the origin, implementation, and impact of the BedZED project.

Background
The inspiration behind BedZED originates from the concept ‘sustainable development’.[9] The term first appeared in an official African document signed in 1969 at the International Union for Conservation of Nature (IUCN) by 33 African countries. The U.S. adopts that term in the National Environmental Policy Act (NEPA) of 1969, defining it as: “economic development that may have benefits for current and future generations without harming the planet's resources or biological organisms.” This is redefined in the United Nation's Brundtland Report for communities to meet: “the needs of the present without compromising the ability of future generations to meet their own needs.”[11]

Causes
The following influential events of the 20th century partially explain the rising interest in sustainable living that led to BedZED:

Air Pollution Control Act (1955)
This is the first piece of legislation to pass Congress that formally addresses air pollution. This act was passed in response to a series smog-related deaths. While it had no form of enforcement from the federal government, it demonstrated a change in priority: the government’s formal declaration to combat air contamination. [10]

Rachel Carlson's Silent Spring (1962)
This book was the catalyst for the modern day green movement, specifically addressing the overuse of pesticides. It called for people to be stewards of the earth, shifting public mindset from a cowboy economy to Buckminster Fuller's spaceman economy. [10]

Earth Day (1970)
The first national Earth Day was held to address the seriousness of environmental problems facing the country. This was a significant step towards normalizing sustainability and environmental protection. [10]

Kyoto Protocol
This is an international treaty that extends the UN’s 1992 United Nations Framework Convention on Climate with the purpose of reducing carbon emissions. This international conference brought the issue of environmental impact and sustainability to the global scene. [10]

Contributors
BedZED was primarily designed in 1997 by British architect Bill Dunster, founder of Zedfactory. Housing association Peabody Trust was recruited as the developer of the site. The project was a collaboration between Dunster, sustainability charity Bioregional, engineering consultants Arup and Ellis & Moore, and cost consultant Gardiner & Theobald.[3][6]

Technology
The introduction of experimental technologies, allowed BedZED to meet its sustainability goals while maintaining a comfortable standard of living. The lack of heritage of many of the major technologies increased risks associated with the development.

Heat and Power
BedZED was designed to greatly reduce its residents' carbon-dioxide emissions by consuming no fossil fuel for heat and power.


 * The development initially used a woodchip-burning combined heat and power (CHP) plant, generating both heat and electricity for the site. However, the plant had to shut down every night due to noise concerns, and resultant tar build-up and condensation caused the plant to be frequently taken out of service. In 2005, the CHP plant was replaced with conventional natural gas boilers and power grid electricity purchased on a green tariff.[6] In 2017, a membrane bioreactor[8] was installed to fully power the district heating system.
 * 777 square meters of solar panels supplied 11% of the district’s daily electrical power usage.
 * BedZED’s housing blocks are designed with a passive housing approach. All walls and windows have high levels of insulation, airtightness, and thermal mass, helping to maintain comfortable temperatures year-round. The buildings are solar-oriented, arranged in east-west rows. The south, sun-facing sides contain sunspaces behind large insulated windows, using the greenhouse effect to warm the air within. This serves as the key solar gain feature of the buildings, allowing for maximum use of the sun’s warmth for space heating. Stepped terraces on the blocks’ north-facing sides descend at an angle to prevent shading of the next row at times when the sun is low in the sky.BedZED roofs 2007.jpg
 * The buildings use roof-mounted wind cowls for ventilation with minimal heat loss. Vanes on the cowls angle them to the wind, allowing fresh air to be brought into homes. The outgoing air warms the incoming air through a built-in heat exchanger.[6]

Sustainable Water
BedZED is in a region facing significant water stress, so it was designed to minimize unnecessary water consumption.


 * Homes have water-efficient shower heads, taps, toilets, and washing machines.
 * ‘Green roofs’ seeded with drought-resistant sedum plants soak up rainwater to protect overloaded sewer systems.
 * The initial attempt to collect rainwater runoff from the roofs and recycle it proved unsuccessful due to excessive contamination from local fauna.
 * A wastewater treatment plant was designed to filter and recycle waste using organisms varying from bacteria to macro-vegetation. The use of this treatment plant was discontinued after failure to meet water quality standards.[5][6]

Environmental Impact
BedZED was created under the overarching environmental framework of one planet living. This sustainability framework developed by Bioregional pursues a standard of living which allows for sustainable consumption of one planet’s worth of resources by the year 2050. This consumption is based on population growth expectations, limiting each person to 1.2 global hectares of productive land, reserving 20% of the planets productive land for wildlife and wilderness.[1]

BedZED in Comparison to Sutton:
Sutton is a conventional development of a similar size and mix to BedZED.


 * 53% reduction in travel carbon footprint.
 * 36% reduction in gas consumption.
 * 32% reduction in CO2 from home heating and electricity.
 * 27% reduction in electricity consumption.
 * 23% reduction in total carbon footprint.[6]

Cleaner Living

 * During construction of BedZED, locally sourced and recycled or reclaimed building materials were prioritized. Roughly 52% by weight of construction materials were sourced within 56 km of the site. Roughly 15% by weight of materials were recycled or reclaimed.[6]
 * 60% of waste by weight is recycled or composted.
 * 86% of BedZED residents buy organic food and 39% grow some of their own food.

One Planet Comparison

 * Sutton currently consumes 5.24 global hectares per person which, if used as a standard for an entire planet’s population, would equate to 2.9 planet’s worth of resources by 2050.
 * The average BedZED member consumes approximately 4.67 global hectares worth of resources. If used as a population standard this would equate to 2.6 planet’s worth of resources by 2050.
 * If the CHP plant was fully operational it is estimated the average BedZED member would consume 3 global hectares worth of resources. Used as a population standard, this would equate to 1.7 planet’s worth of resources by 2050.
 * To reach the one planet sustainability goal for 2050 would require a 66% reduction in resource consumption from the Sutton baseline and a 90% reduction in carbon footprint.[1]

Social Impact
BedZED encourages its residents to adopt sustainable lifestyles, lowering their utility costs and creating a tight, like-minded community. It was designed to be an appealing place to live to promote sustainable living.

Transportation
BedZED was designed to reduce greenhouse gas emissions from travel by encouraging environmentally-friendly modes of transportation among its residents.


 * The district has 81 car parking spaces, or 0.6 spaces per home, which discourages car ownership.
 * A car club service allows members to rent fuel-efficient, low-emissions hybrid cars parked in the district.
 * Bicycle stands and storage are common throughout the district.
 * The area has ready access to public transport, with three bus routes, a train station, and a tram stop all in the immediate vicinity.[6]

Community
A large part of making an appealing living space is building a strong sense of community among its residents. Design choices of the district serve to encourage neighborliness among those living in the eco-village.


 * The village has many indoor and outdoor community spaces. Residents Lukas and Elaine say: “It’s a bit like living in a village with a great mix of people.”


 * All streets between the housing blocks are traffic-free, encouraging mingling and recreation.
 * The district has a relatively high housing density. This is viewed positively by locals. BedZED residents Tom and Janette say: “Somehow the high density and closeness of residents has been reversed from a negative to a positive.”


 * 84% of residents felt that the community facilities were better here than in previous neighborhood. Resident Jacqui says: “My energy bills are about a fifth of what they were in my previous home.” Residents knew an average 20 neighbors by name. Resident Helen says: “We appreciate ... the community aspect, with lots of people talking to their neighbors”[6]

Conclusion
BedZED is the first attempt at sustainable living in a major housing development. It demonstrates that a large shift towards sustainable living does not require sacrifice or discomfort. Ecologically conservative living is possible but some of the technology and innovations have proved difficult to adopt. BedZED was incapable of limiting resource consumption to a sustainable level to reach the one planet goal, however this project made progress toward reaching this goal. Compared to similarly sized communities, it consumes less resources and operates more sustainably. BedZED provides a concrete example of how society must operate to conform to a spaceman economy.

Further Works
BedZED is a pioneer for large-scale ‘carbon neutral’ communities. It defined the framework for similar communities, and inspired a variety of other sustainable developments.[4] Projects of this nature would not be possible without continual advancements in sustainable technology. For other examples of sustainable communities, see also: Ecovillages