What is air pressure testing?
So – what is air pressure testing? Air pressure testing calculates the air tightness of a building, known as its ‘air permeability’ or ‘leakage’ rate. Air leakage is air that escapes the building via uncontrolled means. Leakage can occur through gaps, holes or cracks in the fabric of the building. Excessive air leakage can affect the building’s energy efficiency, making the building less energy efficient and more expensive to run.
why do i need air pressure testing?
Now we’ve covered ‘what is air pressure testing?’, we’ll explain why you need it.
Part L1A and L2A (England & Wales), Section 6 (Scotland) or Part F1 (Northern Ireland) of The Building Regulations require air pressure testing. Air pressure testing has been mandatory for all new build residential and commercial properties in England, Wales and Northern Ireland since 2006, and in Scotland since 2010.
This is to make sure the building meets or exceeds the air permeability rating specified in your design stage SAP or SBEM calculations. Maintaining a high level of air tightness within a building helps with energy efficiency. For instance, air entering and escaping a building can lead to lost heat and cold draughts.
Failing to maintain air tightness can result in up to 40% heat loss. If you’re investing in energy efficiency measures, such as a new boiler or extra insulation, your efforts could be in vain if the building’s air tightness isn’t adequate.
In some cases, extended commercial properties require air pressure testing. For instance, commercial extensions that have a total useful floor area 25% greater than the existing building or larger than 100m2 will need testing. Although not legally required for residential extensions or conversions, many people have the test performed for peace of mind.
How is it done?
- We’ll temporarily install a large fan, usually in a doorway
- Next, we will temporarily seal openings to the property and switch the fan on
- The air pressure is gradually increased and decreased, recording the pressure differential at each step
- The total air flow required to achieve a pressure differential of 50 Pa is calculated and divided by the total building envelope area. This provides the leakage rate in m³/h.m² @ 50 Pa
- This calculation will show the building air tightness, or air permeability
Contractors can continue work within the property but all windows and doors have to remain closed for the duration of the test.
When should it be carried out?
How long will it take?
What happens if my building fails?
- Insufficient sealing around windows and doors
- Spaces behind fitted units, such as in the kitchen or bathroom
- Cracks around sockets and other electrical inputs
- Gaps where the external wall meets a floor
- Space around any pipework leading into the building
At UKBC, we want your building to pass. To make sure, we provide consultation and on-site training for your contractor about reducing leakage rates in problem areas.
However, if your building does fail, we offer a number of services to ensure that the process is ultimately a success. Our technician will give you full feedback and suggestions to help you make changes which will ensure a pass during the second test.
For more information or to arrange testing, call us on 01455 634855 or request a QUICK QUOTE.