BedZED Beddington Zero Energy Development

Sutton, England
2002

The design of the project integrates environmental and sustainable goals. Features include: roof gardens, sunlight, solar energy, reduction of energy consumption, and wastewater recycling.

  TRANSPORTATION

A green transport plan promotes walking, cycling, and the use of public transport. BedZED's green transport plan was written into the land purchase contract. Private car ownership at BedZED was limited with the target for fossil fuel car miles to be 50% of the average. The development is located within walking distance of commuter rail and bus lines. There are only 0.5 parking spaces provided per unit. The vehicle miles traveled per person per year is 2304, 65% less than the UK average.

BedZED was the first low car development in the UK to incorporate a car club. The onsite car club, called "ZEDcars," has an internet-based booking system. The resident-only car share uses electric cars powered by the photovoltaic array.

The development also features community cycling facilities.

  STORMWATER MANAGEMENT

Rainwater is collected and used for toilets and irrigation. A storm water collection swale is designed as a wildlife corridor. Porous block paving is used as permeable paving throughout the project. Rooftop gardening is facilitated with 12 inches of soil.

  ENERGY

The orientation, program, and landscape at BedZED are designed with integrated passive solar strategies. First, a row house design is used to reduce exterior wall surface. The buildings are elongated from east to west to maximize southern exposure and ease of solar control. A solar conservatory on the south side of the living units captures passive solar gains. The building program is organized with heat-producing commercial properties on shady north side of the buildings. This also serves to buffer the residential units. High thermal mass and super insulation elements are used throughout the project. The R-value for the walls and floor is 56 and the R value for the roof is 51.6. The windows have a U-value of 0.21. Air leakage is 0.14 cfm 50/sf. The heat recovery ventilation system is 70% efficient.

The total energy consumption for the project is 26 kBTU/sf/yr. The combined energy demand for space heating and domestic hot water is 15.2 kBTU/sf/yr, which is 57% less than the UK average for domestic hot water and 88% less than the UK average for space heating.

Annual total energy use compared across all international case studies - not normalized for climate.
View annual total energy use compared across all international case studies - normalized for climate here.

To meet energy demands, BedZED installed a biomass-fueled power plant.

A biomass-fueled combined heat and power plant (CHP) and a photovoltaic array were intended to meet the heating and power needs of the development. The photovoltaic system is a 109kW array. It provides 10-20% of the electricity consumed at BedZED.

The combined heat and power system was designed to provide both electricity and hot water. Hot water is distributed around the site via a district heating system of super-insulated pipes. Supplemental heat, should residents or workers require it, is available from a domestic hot water tank that doubles as a radiator in home or office. The fuel for the CHP plant is tree surgery waste that would otherwise go to a landfill. Wood is considered a carbon neutral fuel because the CO2 released when the wood is burned is equal to that absorbed by the tree as it grew. BedZED also has wind-assisted heat recovery ventilation.

The combined heating and power plant has been shut down due to operational difficulties. As a result, the development is not a zero energy development.

The majority of the residents find their homes to be uncomfortably warm in the summer. This may be a result of residents neglecting to use operable windows for ventilation, combined with a lack of proper shading in conservatory spaces.

  POTABLE WATER

The average indoor potable water use at BedZEd is only 20 gallons per person per day. This is 50% less than the UK average. 4 gallons per person per day of captured rainwater, used primarily for toilet flushing, supplement indoor water use.

Annual total energy use compared across all case studies - normalized per heating degree day

  WASTE WATER

A living machine to process wastewater was built and operated for less than a year before it was shut down due to operational expense.

  SOLID WASTE

The development produces 231 pounds of solid waste per person per year, 68% less than the UK average by weight. Every BedZED home incorporates a color coded, segregated under-sink bin. The colors relate to the type of waste: green for compostable, vegan waste; two grey sections for glass, plastics, paper, and tins; and brown for non-recyclables.

Compost is counted separately. There is on-site composting of food waste with worms.

  MATERIALS

The project used recycled and reclaimed materials, including FSC certified wood, throughout the development. Most of the bulk materials were sourced from within 35 miles of the site.

The walls are comprised of 4 inch concrete block with 12 inches of insulation on the exterior and clad on the outside with 4 inch brick. The windows are wood-frame, argon-filled, triple glazing with double glazing for the solar conservatory.

The R-value for the walls and floor is 56 and the R value for the roof is 51.6.The windows have a U-value of 0.21.