Atrium
An enclosed glazed space, normally in the middle of buildings of 3 storeys or more, which allows light into the centre and traps heat.

Autonomous Housing
Dwellings which allow a more self-sufficient lifestyle because they can function independently of public water/drainage and utility systems.

Balancing Pond
Water storage area used to prevent flooding from surface water drainage that allows a gradual release into adjacent water courses.

Biomass
Forestry and agricultural residues and crops (such as willow) which are used as a fuel to produce electricity and heat.

Brownfield Site
Previously developed land that is or was occupied by a permanent structure (non-agricultural use) and its associated fixed surface infrastructure.

Co-generation
The production of electricity using waste heat or steam from industrial processes.

Combined Heat & Power (CHP)
A system which utilises waste heat from electricity production to provide hot water and space heating for neighbouring buildings.

Condensing Boiler
A high efficiency boiler which incorporates an extra heat exchanger so that hot exhaust gases can pre-heat the water in the boiler system.

Cowl
A cone shaped cap, commonly turning with the wind, used to improve the draft of a chimney, ventilation shaft etc.

Desire routes/ lines
Shortest-line routes between a place of origin (eg public building) and one or several destinations.

District Heating
Heating systems which distribute steam or hot water to a number of buildings across a district. Heat can be provided from variety of sources, including geothermal, CHP plants, waste heat from industry and purpose built heating plants.

Embodied Energy
Amount of energy consumed in the extraction, manufacture, transport, construction and assembly on site of building materials. It will also include the energy costs of disposal of waste or surplus materials.

Fossil Fuels
Fuels formed from animal or plant remains that become fossilised or trapped in geological strata, chiefly coal, oil and natural gas.

Geothermal
Energy derived from naturally occurring underground heat, usually recovered by use of a heat pump or by tapping heated water.

Grey Water
Water consumed within buildings, except water from toilets, that is stored and reused for other purposes e.g. garden irrigation.

Home Zone
A street or group of streets designed or converted to suit the needs of pedestrians and cyclists rather than motorists, which can open up the street for more social/leisure uses.

Insulation
The filling or cladding of walls and other external/unprotected areas of buildings such as roof spaces to prevent loss of heat through draughts.

ISO 14001
The international standard for environmental management.

Listed Buildings
Buildings or structures of special architectural or historic interest that are included on a list, approved by the Secretary of State, giving key details of each building. They require special consent for any proposals for their alteration, extension or demolition.

Passive Solar Gain/ Heating
Natural heating that results from the sun’s heat penetrating a building (mainly via windows) and being trapped within.

Payback
The time period required for savings in energy or water bills to outstrip the initial financial investment in building improvements.

Photovoltaic Cells/ Arrays (PV)
Solar panels that produce electricity from light, rather than heat - and thus work even if the sun is not shining. ‘Photo’ refers to light, and ‘voltaic’ means they turn it into volts, that is, electricity.

Renewable Energy
The transfer of heat and/or the generati on of electricity from naturally occurring, self-renewing sources such as wind, sun and water.

Secondary Glazing
An independent system of glazing fitted to the inner window frame. The gap between the outer and inner window determines the level of insulation, so that larger gaps give better insulation, notably for noise.

Solar Panels
Panels, usually installed on roofs, which use the sun’s energy directly to heat water, without using electricity.

Sustainable Building
Buildings that are designed and constructed to the highest environmental standards, (especially in order to minimise the use of energy, water and scarce minerals/timber), that are economic to run over their whole lifetime and are sufficiently flexible to meet the needs of future generations.

Swale
A grass covered, broad and shallow depression which leads water overland from drained surfaces to a storage or discharge system. They provide temporary storage for storm water and reduce peak flows.

Thermal Mass
Refers to the solid part of a building, such as block or brickwork, in which heat energy, from the sun or other sources, is absorbed, stored and then gradually given off.

Originally completed: July 2004

Last reviewed: February 2005