New homes are becoming increasingly sophisticated in their build and energy efficiency is a key element of this. Over 25% of the UK carbon dioxide emissions are generated by home energy use* and so the Government is looking for new homes to become zero carbon homes.
As a result, Building Regulation changes have made air tightness testing mandatory for new homes; a sample of new homes on a development, including one of each type of property, must now undergo air pressure testing.
Why do homes need to be airtight?
Whilst insulation keeps a home warm, the benefits are lost if warm air can escape from the building and cold air can creep in. If a property is not airtight then up to 40% of the heat can be lost** making it very inefficient in terms of energy. When air tightness is achieved then the energy required to heat or cool a home is reduced, saving energy and money.
It is important to note that new homes should not be completely airtight; for the comfort and safety of the occupants, there must be controlled ventilation in place to ensure fresh air enters the property. This ventilation is provided using trickle vents, extract vents and mechanical ventilation.
Why is airtightness testing important?
Air pressure testing ensures a brand new property meets the Building Regulation standards. Air tightness testing also identifies any leaks within the building which can then be rectified. Common areas for leakage include service entry and exit points, such as service pipes, cables as well as extractor fans.
When is air pressure testing required?
It is recommended it is carried out three times during the build process for a new home:
Initial airtightness test; once the property is weathertight and has windows and doors in place
Second airtightness test; after the installation of the services in the property
Final airtightness test; once the property has been finished
By testing at these three key stages, any issues can be promptly identified and rectified quickly and easily, rather than waiting until the end of the build. If air tightness testing is only carried out once the build is complete then issues can be difficult and costly to fix as everything is in place and finished.
How many new homes need testing on a development?
The number of new homes requiring air pressure testing on a new development depends on the size of the site. If there are 4 new homes or less then only one of each of type needs air tightness testing. If there are between 4 and 40 new homes then two air pressure tests of each type are required. For large developments where the number of new homes exceeds 40, at least 5% of each type must be air tightness tested. This sampling frequency can be reduced to 2% if the first 5 tested achieve design air permeability.
How can Falcon Energy help?
Falcon Energy are affiliated to IATS, the Independent Air Tightness Testing Scheme. We are fully qualified in air tightness testing so you can be assured you are in safe hands with us.
For a free, no obligation quote on air tightness testing for your residential or commercial property, or to simply discuss your requirements, get in touch on 01403 253439 or email info@falconenergy.co.uk. Alternatively, fill out our contact form here and a member of the Falcon Energy team will be in touch.
*NHBC Foundation, 2009. NF14: Zero carbon homes – an introductory guide for housebuilders. IHS BRE Press, Bracknell
**Webb BC, Barton R, 2002. BRE report BR448 Airtightness in commercial and public buildings.