Air Tightness Testing

One of the UK’s leading providers of Air Tightness Testing, with over 20 years’ combined experience undertaking air pressure tests for domestic and commercial buildings nationwide. 

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With our network of assessors nationwide, we can perform your air tightness test within 5 days and often sooner with our 24-hour service when required.


We have performed air tests on over 2000 dwellings to date and our extensive experience makes the process as smooth and easy as possible.

Cost effective

We constantly benchmark our prices to offer the most cost-effective air tightness testing services. 

How it works

A suitable date for the test is scheduled.

We supply your Registered Certificate of Air Permeability Test.

We review your plans and make recommendations if we identify potential leakage paths.

The tests are carried out on-site using blower door testing equipment.

Meet our qualified Air Tightness Test assessors

Our Air Test Assessors are trained and registered with ATTMA or IATS. They undergo regular training and development to ensure you receive a service that goes above and beyond simply completing the calculation. 

Our key testers are:

Sam Millard

Jonathon Hill

Dan Chadwick

What is Air Tightness Testing?

Air Tightness Testing (also referred to as Air Permeability, Air Pressure and Air Leakage Testing) is a means to quantify the extent to which buildings leak air through gaps in the building fabric. The requirement for Air Leakage Testing is driven by Part L of Building Regulations. 

Air leakage is a vehicle for energy wastage, resulting from the increased loads placed on the space heating system. Improving air tightness is an important factor in reducing carbon emissions in buildings. 

The air test is carried out on completion of the dwelling and the result is entered into the Design Stage SAP calculation to produce the As Built SAP calculation and EPC. 

Leakage points:

Diagram showing air leaking through gaps in a house

Why use C80 Solutions for your Air Tightness Testing?

We have performed Air Tests on over 2000 dwellings to date.

We have over 20 years combined experience carrying out Air Tightness Tests.

All our test engineers are trained and registered with ATTMA or IATS.

We provide a National Coverage.

An Air Tightness Test is carried out to find out if a building is leaking air through gaps in the building fabric. This is uncontrolled leakage, not just the normal ventilation through trickle vents and other forms of controlled ventilation. High levels of air leakage would mean heat escaping and energy being wasted, therefore increasing the carbon emission in buildings. 

Current building regulations state it is a requirement of Approved Document L that any dwelling tested must achieve an air pressure test result of less than, or equal to 8m3/h/m2, at a pressure differential of 50 pascals.  

New dwellings must achieve an air leakage of around 5m3/hm2 or less per hour, per square metre of envelope area. 

The test (also known as an air permeability test, air pressure test and air leakage test) is carried out on completion of the dwelling. The test result is passed to the SAP assessor and entered into the Design Stage SAP calculation to produce the As Built SAP calculation and EPC. 

It takes about two hours for the test – the dwelling/property has to be completely empty. You will need to prepare the building before our arrival. Contact us for our handy checklist to tick off as you prepare the dwelling. 

Pricing will vary depending on size and complexity of the project. 

  • From the earliest drawings set air tightness goals. 
  • Brief the construction team and make sure all tradesmen know this is going to be an airtight build. 
  • Have an inspector visit during the build to review progress. 
  • Use an air tightness testing kit and test for air leakage during the build while there’s still a chance for remedial work to be carried out. 
  • Test again at the end before your official Air Tightness Test.  

Check for visible leaks in the following places: 

  • Windows: Check the seal beneath the sills and around the frames. 
  • Doors: Check the seal around all external door surrounds (especially French doors). 
  • Drainage traps: Check they are filled with water or sealed with tape. 
  • Skirting and coving: Check above and below all skirting and coving, sealing where necessary.  
  • Meter Boxes: Check all external supplies are sealed appropriately. 
  • Light Fittings: Check the seal around all light fittings and switches.  
  • Radiators / Fans / Heaters: Check the seal around all pipes and wires. 
  • Boilers: Check the seal around the boiler supply and flue. 
  • Extractor Fans: Check around the edge of the extracts, only the front of the grill can be sealed.  
  • Cooker Hoods: Check the seals around all penetrations.  
  • Soil pipes: Check the seal around all soil pipes and sink waste pipes especially those boxed in or behind kitchen cabinets. 
  • Bath Panels: Check all pipes behind bath panels are sealed properly.  
  • Hot water tank: Check the seal around all supply pipes.  
  • MVHR: Check seal around all terminals.  
  • Chimneys: Open fireplaces must be sealed prior to our arrival.  
  • Air Bricks: Does the dwelling have air bricks these should be sealed for the test.  
  • Tumble drier extracts: Check the seal around the extract. 

Book your Air Tightness Test

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