Measures Database
| ENERGY: AIRTIGHT CONSTRUCTION |
Fit as standard Applicable to all sites Low cost Easy implementation No EcoHomes credits achievable |
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Description |
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 Ventilation is needed in buildings to provide fresh air for occupants, to dilute pollutants, and to exhaust heat gains. In the design and construction of modern buildings the aim is to provide an airtight envelope and introduce ventilation in a controlled manner, either naturally or mechanically.Building to the robust construction details that accompany Part L of Building Regulations can reduce unplanned heat loss resulting from air leakage through buildings (Limiting thermal bridging and air leakage: Robust construction details for dwellings and similar buildings The Stationery Office. 2001.) Measures include: ensuring sufficient laps on vapour barriers, sealing around services and other penetrations, sealing at the junctions between components and careful detailing to avoid unwanted air paths. The air permeability of a home can be tested by pressurising it with fans on completion. CIBSE TM23 (Testing Buildings for Air Leakage) sets out good and best practice air permeability rates for different building types. |
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Cost |
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| Cost of providing an airtight building envelope has been estimated at around £80 per dwelling, based on 50 dwellings in a single development. |
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Benefits |
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Local Authorities |
Where local authorities have climate change strategies, including CO2 reduction targets, measures to seal buildings will contribute towards energy savings and help in reaching those targets, Undertaking works to seal domestic dwellings such as sealing cracks around doors, windows and service entries in homes of the fuel poor, could help bring families out of fuel poverty (through decreased fuel bills). |
Global Environment |
One quarter of the UKs CO2 emissions every year originate from the energy we use to heat and light our homes. Reducing energy use in dwellings will reduce the amount of fossil fuels required and volume of CO2 emitted. |
Occupier |
Measures that reduce air leakage help to reduce heat loss in winter and should lower fuel bills. These measures can bring energy cost savings and improved internal comfort for householders. Airtight construction can also prevent polluted air entering the home, and reduce cold draughts. |
Developer |
There is little benefit to developers at present, however, under proposed changes to Part L1 of Building Regulations it will become compulsory to test air leakage in dwellings and achieving reduced air permeability will assist in complying with regulations. |
Implementation notes |
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| When increasing the air tightness of a building envelope, designers must ensure that adequate ventilation is provided by the ventilation systems. Adequate means of ventilation for combustion equipment and for the removal of moisture from dwellings should always be considered. | |
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