Air test: dwellings
Tackling air leakage, where conditioned air is lost through gaps and cracks in the building fabric, represents an important method to improve the carbon footprint of a building.
Air leakage testing is the method used to quantify the amount of air that is being lost. This test, which is sometimes referred to as air permeability testing or air pressure testing, gives a result expressed as a quantity of air leakage (m3 per hour) per square metre of building envelope.
Under Approved Document L1A, air leakage testing is a mandatory requirement. Each dwelling tested must achieve a maximum air permeability rate of 10m3/h/m2.
If the aim is to comply with a specific carbon emission target, then a lower air permeability rate may be required. The design-stage SAP report for each particular dwelling will provide details on the required air permeability rate.
Excessive air leakage can lead to:
- Unwanted heat loss
- Colder homes
- Increased heating costs
- Greater CO2 emissions (resulting from additional heating)
Home energy use is responsible for approximately 27 per cent of UK carbon dioxide (CO2) emissions and poor airtightness can be responsible for up to 40 per cent of heat loss from buildings.
What happens in the event of a fail?
It is common to achieve a first-time pass. However, should this not be the case, then we will identify where problems exist and provide options for how these could be addressed. If improvements can be undertaken on the day, we will re-test at no additional charge. If the time-frame is more protracted, we will arrange for our test engineer to attend your site at a different day/time once the work has been completed.
For added piece of mind, we can provide design reviews prior to construction commencing, and support and advice thoughout the build.
How to improve a dwellings air tightness
- Refer to the Communities and Local Government accredited construction details.
- Seal gaps around pipes and cables where these pass through walls, ceilings and floors.
- Make sure all mastic and caulking has been applied.
- With drylining, if the plasterboard sheets have not been sealed at the junctions with the ceiling and floor (in addition to sheet to sheet) air can leak through the gaps.
- Apply draught proofing to gaps around doors and windows.
- Ensure any loft hatches fit into their apertures and apply draught stripping between the hatch and frame.
- Repair damage to mortar joints and fill any holes in the external walls.
- Maintain a good seal around boiler flue pipes where they pass through the external wall or ceiling.
Is an air leakage test necessary?
L1A 2013
Although exceptions do exist, if you have built a new dwelling then in most cases an air leakage test will be required for compliance with Approved Document L1A 2013.
In cases where a development of two or more dwellings is taking place, the test should be carried out on the lower of:
Three units of each dwelling type; or 50 per cent of all examples of that dwelling type.
If a development of no more than two dwellings is taking place, then by using an assumed value of 15m3/h/m2 within the DER/TER calculations, it might be possible to avoid the pressure test. Information regarding suitability will be provided by the SAP assessor.
L1 2021
Approved Document L1 2021 came into force on 15 June 2022. For developments being assessed under L1 2021 there are no exemptions for air leakage testing and the maximum design air permeability rate has been reduced to 8m3/h/m2.
Why choose Achieve Green?
We are members of the Air Tightness Measurement Association, meaning our test certificates will be recognised for Building Regulation sign-off.
Our experienced air test engineers have an extensive track history, testing all varieties of buildings.
Our test engineers will be on hand to answer any questions and provide free advice and support throughout the construction process.
We fit around you, attending site at a time that is convenient and ensuring test certificates are ready for issue within 24 hours.
All of our test engineers are CSCS certified.
By using an ISO 9001 accredited organisation such as ours you can be confident in receiving a consistently high quality of service.
New dwelling Building Regulation compliance pack
- Part L: SAP calculations and Energy Performance Certificates.
- Part L: air leakage testing.
- Part E: sound insulation testing.
- Part F: extractor fan flow-rate testing.
- Part G: water calculations.
- Part O: dynamic thermal modelling.
COMPETITIVE
Fast and accurate assessments at a competitive price.
EXPERIENCED
Comprehensive advice and support to ensure you arrive at the most economic and feasible solution to achieve compliance.
QUALIFIED
You can take comfort that the certificates we provide will be accepted as evidence for Building Regulations sign-off.
VALUE
Best quality advice, at a price that offers real value for money.
Testimonials
We are an RIBA Chartered Architectural Practice based on the South Coast, and have used the services of the Achieve Green team in Tunbridge Wells on countless projects over many years, mainly for the preparation of SAP calculations but also energy statements and air pressure testing across a broad range of projects. They have offered us invaluable practical advice on more complex projects to ensure compliance with the ever evolving statutory standards and we have always found them to provide a prompt, efficient, friendly and cost effective service and would not hesitate to recommend them.
Lightbox Architecture Limited
We have found the Achieve Green team to be highly experienced, specialised and competent. Advice is constructive and their approach to projects is strategic, ensuring the most effective solutions are taken forward. The team has a comprehensive understanding of planning requirements and appreciates how these translate into technical and on-site delivery. We highly recommend the team and look forward to working with them on forthcoming projects.
Kitewood Estates Ltd
As a business we have been involved with Achieve Green for a number of years. Their proactive involvement in our projects from design through to completion has enabled us to continually improve the energy efficiency of all our homes. The prompt and efficient service has meant they have become an integral part of our design team.
Panfile Ltd
I have been working with Jonathan and his Achieve Green team in Tunbridge Wells since 2011 on a range of projects from Schools, new build housing to straightforward extensions. They are very knowledgeable and efficient and have provided invaluable input to projects over the years ensuring that as a designer I can put forward the most cost effective solutions to complying with Part L.I always recommend Jonathan if ever anybody is in need of SAP and compliance testing services.
Bradbury Design Ltd