ECOPEDIA: GLOSSARY
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
X
Y
Z
A
Air Changes per Hour (ACH):
The number of times a volume of air is entirely replaced per hour.
Argon:
An inert, non-toxic gas sometimes used in double glazing for its insulative quality.
B
Biodegradable:
Able to break down naturally by action of living organisms.
Biofuel:
Crop-based fuels that absorb carbon from the atmosphere whilst they are growing and return it to the atmosphere when burnt.
Blackwater:
Water that has been contaminted with food, animal or human waste.
British Thermal Unit (BTU):
The amount of thermal energy required to raise the temperature of one pound of water by one degree Fahrenheit. Often used to measure boiler output.
Brownfield land:
Land that has previously been developed.
Brownwater:
Water that has been in contact with human soil.
Building Envelope:
The external 'shell' of a building, comprising its outermost elements, (e.g. foundations, doors, windows, external walls and roof).
C
Calorific Value:
The amount of thermal energy produced by the complete combustion of a given weight of fuel.
Carbon Footprint:
The total area of land (based on average area assumptions) required to absorb the carbon dioxide expelled into the atmosphere by one or more activities. This is a common measurement of an individual or organisation's impact on the environment. See also: Carbon Footprint*
Carbon Neutral:
Where net carbon emissions and absorption are zero.
Carbon Offsetting:
A way of compensating for carbon dioxide emitted by providing a means of absorbing the same amount from the atmosphere (for example, by planting trees).
Code for Sustainable Homes:
The Code measures the sustainability of a home in terms of a 1 to 6 star rating system (also referred to as 'levels'). It is based on (but replaces) the BRE 'EcoHomes' rating system.
The government has proposed that assessment by the Code should be mandatory for all new build homes.
Combined Heat and Power (CHP):
A means of harnessing the heat created as a by-product of generating electricity to produce both heat and electricity efficiently from a single fuel source. See also: District CHP
Compact Fluorescent Lamp (CFL):
These are a smaller version of the traditional 'tube light,' and are increasingly referred to as halogen or 'low energy' bulbs.
Cowl:
A chimney hood used to direct exhaust more efficiently by increasing draft and preventing backflow.
D
Decent homes:
Homes that meet the Decent Homes Standards by being (amongst other things) warm, weatherproof and having reasonably modern facilities.
District CHP:
Power which is generated for a local group of homes, for example, a street or a block of flats (usually under two hundred).
Diurnal:
A daily cycle of fluctuations, for example, light and heat levels between day and night. See also: Thermal mass
Double Glazed Unit (DGU):
Two panes of glass with a gas in between to act as insulation. See also: Argon
Dual Flush:
Manual flush cistern with two varying flushing volumes depending on the matter being disposed of. Also compare: Low Flush
Dwelling Emission Rate (DER):
The annual Carbon Dioxide emissions (in kilograms) from space heating, water heating, ventilation and lighting per sq m of floor area. Also known as: Building Emission Rate (BER), Carbon Emission Rate (CER)
E
Eco Footprint:
The average area of land and water required to support one or more activities in terms of consumption of resources and absorption of Carbon Dioxide. See also: Carbon Footprint
Embodied Energy:
The total amount of energy already involved in the creation of a particular product, including any transport and labour. It is important to consider both embodied and operational energy, as an improvement in operational energy may be mitigated by the cost in embodied energy. For example, retaining the building envelope and refurbishing the internal space, rather than demolition and reconstruction, can save embodied energy although operational improvements may be minimal.
F
Forestry Standards Commission (FSC):
The FSC is an organisation setting and assessing international standards for responsible forest management. Accredited sources are granted permission to use the FSC trademark. Sustainable forest management involves gaining a range of benefits (e.g profits, energy, timber, leisure, carbon absorption and moderation of temperature and rainfall) from forests over time.
Formaldehyde:
A chemical harmful to health over even short period of time and known to cause cancer. Whilst naturally occurring in the atmosphere, higher levels of exposure come from its use in paints, carpets, insulation, adhesives, MDF and other particle boards. Some pre-1980s foam insulation can continue to emit formaldehyde for many years.
G
Geothermal energy:
Thermal energy obtained from natural heat under the surface of the earth.
Green Roof:
A roof which is partially or completely covered with plants, creating a lag time between peak rainfall and peak discharge into drainage systems. Green roofs are also often used for filtration of rain or greywater.
Greenbelt:
Land - usually surrounding urban areas - that is protected from development to prevent 'urban sprawl' and protect the countryside.
Greywater:
Wastewater generated by household processes that has not been in contact with human waste. See also: Blackwater, Brownwater
H
Heat exchanger:
A piece of equipment that passively and efficiently transfers heat, usually from hotter to colder areas. Used in solar and geothermal heating and passive stack ventilation.
Heat Pump:
A piece of equipment that requires energy to transfer heat, usually utilising compression/decompression of a liquid or gas. Whilst more energy-intensive than heat exchangers, heat pumps have the ability to transfer heat faster or for the purpose of cooling (from hotter areas to a heatsink).
Home Information Pack (HIP):
A standard set of documents (some optional) provided by the seller of a home to potential purchasers, aimed at speeding up the conveyancing process.
The pack can be compiled by anybody, but must include an Energy Performance Certificate carried out by an approved home inspector.
On 14 December 2007, it became compulsory for compilation of a pack to be started prior to marketing of all homes.
Compulsory documents include, amongst others: Energy Performance Certificate, standard searches and evidence of title. Optional documents include, amongst others: Home Condition Report, legal summary and home use/contents forms.
Hydrogen fuel cell:
A piece of equipment using a chemical catalyst (which never runs out) to join a fuel (hydrogen) and an oxidant (oxygen from the air) to create electricity. When using pure hydrogen as a fuel source, heat and water are the only by-products. As fuel cells do not have moving parts they rarely require repair/replacement. The reverse of this process (electrolysis) can produce hydrogen from water. Also known as: PEMFC
I
Incandescent bulb:
These are traditional 'edison bulbs' using a filament burning in an inert mixture of gases. CFL bulbs are now around 6 times more efficient. See also: CFL
K
KiloWatt-hours (KWh):
One watt of power used for a thousand hours, or any equivalent ratio. A unit of measurement for the consumption of power (commonly used for billing electricity).
L
Lifetime Homes:
A set of standards set by government aimed at ensuring that homes are flexible and adaptable to cope with life changes (such as having children, becoming disabled or growing old) quickly, cost effectively and avoiding upheaval by being thoughtfully designed.
Light Emitting Diode (LED):
An efficient, long-lasting light emitter, clusters of which can be used to form bulbs. Low heat emissions also minimise the requirement on cooling equipment. However, these are currently expensive and provide light levels best suited for spot-lighting.
Low Flush:
An efficient system of toilet flushing that uses a relatively low amount of water (approximately six litres) without impacting on hygiene. Also compare: Dual flush
Low-E Glazing:
A form of glazing coated to allow light energy to pass through whilst reflecting thermal energy. This reduces the transfer of thermal energy through the glass resulting in a greater U-value. See also: U-value
M
Mechanical Ventilation with Heat Recovery (MVHR):
A piece of equipment which allows ventilation without altering the temperature of a space. See also: Passive Stack Ventilation
Micro-generation:
Generating power on a more local level as opposed to on a national or regional level.
Micron:
One millionth of a metre, or one thousandth of a millimeter. A unit of measurement often used to measure thickness of membranes and sheeting. Also known as: Micrometre
N
National Grid:
The high-voltage electric power transmission network in Great Britain, allowing consumers to access electricity far from its source.
P
Passive:
Functioning by using energy from its surroundings rather than a direct energy source (reactive rather than proactive).
Passive Stack Ventillation (PSV):
A ventilation system utilising the 'stack effect' to create a flow of air. See also: Passive, Stack Effect
Payback:
The time it will take for income/savings to payback an original investment, after which point a profit can be achieved.
Permeability:
The degree to which fluid can pass through a material.
Photovoltaic cell (PV cell):
A piece of technology generating electricity from ultraviolet light. Groups of PV cells are known as photovoltaic arrays or solar modules. Also known as: solar cell
Pipe Lagging:
Insulation around hot water pipes, commonly made from foam.
Potable Water:
Water of a quality fit for human consumption.
Prefabrication:
Manufacturing off-site in factory conditions allowing less time and skilled labour on-site where conditions such as weather are variable. Also allows quality control, reducing the need for over-engineering (which in turn reduces raw materials and load).
R
Rainwater Harvesting:
Collecting rainwater to use un-sanitised for garden irrigation and car washing or sanitised for showers and human consumption.
Rammed Earth:
A method of building that uses a low-impact, natural material comprising a compacted mixture of cement, earth and water. See also: Thermal Mass.
Relative Humidity:
The amount of water vapour present in the atmosphere expressed as a percentage of the maximum that could be present at the same temperature.
Renewable Energy:
Energy derived from sources that will not become depleted in the foreseeable future.
S
Solar Gain:
An increase in temperature caused by exposure to the sun.
Stack Effect:
The rising of warm air creates positive pressure near the top of a space and negative pressure toward the bottom. This creates a flow of air by using passive energy, an effect which is intensified as the space becomes taller. Also known as: Chimney Effect
Standard Assessment Procedure (SAP):
A government-adopted methodology for calculating the energy performance of buildings. It provides energy ratings for HIPs and also works with Part L of the Building Regulations (England and Wales) to measure compliance. See also: HIPs.
Sustainability:
Achieving economic growth, social equity and environmental enhancement.
Sustainable drainage systems (SUDS):
A framework for mitigating issues with flooding and surface water quality by using the best practicable environmental solution.
T
Thermal Mass:
The capacity of a material to store warmth/coolth. Increased thermal mass (for example, through use of concrete and rammed earth) can minimise diurnal fluctuations and benefit from solar gain. See also: Diurnal Fluctuations and Solar Gain.
Trickle Ventillation:
A type of ventilation (usually fitted in window frames) allowing a constant flow of air without creating a cold draught. Also known as: Background Ventilation. See also: Air Changes per hour.
Triple Glazed Unit (TGU):
Three panes of glass with a gas between to act as an insulator.
U
U-Value:
The rate of heat loss in BTUs per hour through a square foot of a surface when the temperature difference externally and internally is 1 degree Fahrenheit. Provides a common method of measuring insulative quality of windows and doors, and recognised in Part L of the Building Regulations.
V
Volatile Organic Compound (VOC):
An organic material that forms potentially harmful vapours at room temperature.
W
Wheelchair Turning Circle:
The space required for a wheelchair to turn comfortably. Lifetime Homes standards recommend provision of a circle of 1500mm or an ellipse of 1700mm x 1400mm within dining or living areas.
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
X
Y
Z | 
