Why do you need Air Tightness Testing?

Air tightness testing is a requirement for all new buildings. Air Tightness is a key factor in achieving an energy efficient building fabric in combination with insulation. The England & Wales Building Regulations require air tightness to be measured through site testing by a competent person (typically someone registered with ATTMA).

Testing is done through a pressure test whereby fans are installed into a doorway of the building and used to create a measurable difference between the pressure inside and outside of the building. The amount of air needed to maintain this difference can be used to indicate the volume of air escaping through the fabric (what would be draughts in the building’s day-to-day life). In order to achieve increasingly challenging energy performance targets, air tightness requirements are becoming tighter.

Our service include:
  • ATTMA L1 Registered air tightness testing for dwellings – houses and flats
  • ATTMA L2 Registered air tightness testing for buildings other than dwellings, including industrial units, schools, hospitals, offices, warehouses, care homes, student accommodation, etc.
  • ATTMA L4 air tightness testing for low energy buildings including Passivhaus, PHI Low Energy, EnerPHit and AECB Building Standard
  • Air tightness testing of smoke shafts for automatic opening ventilation
  • Air tightness testing of floor plenums (to BG 65/2016)
  • Air tightness testing of hospital isolation rooms/suites
  • Air tightness consultancy – design reviews, site meetings, toolbox talks, diagnosis of leakage paths (including smoke testing).

We offer advice and support on achieving air tightness through design reviews, site inspections and toolbox talks/demonstrations on early completion tests. In addition, if buildings fail to achieve their targets, our engineers can demonstrate and explain the issues onsite using the test equipment and/or smoke, report the issues using photographs and snagging sheets then assist with identifying appropriate solutions.

Our approach:

Our engineer will check the building is ready and use fan(s) to pressurise/depressurise the building. Results will be available there and then. If the result isn’t what is required, our engineer will then use the fan to show up the air paths. Depending upon the size and scale of the leakage, often the issues can be resolved the same day and the test repeated with an improved result (often for no additional cost – please confirm with our engineer).

On completion, a certificate is issued within one working day, but can be issued on-site (if agreed in advance). The test certificate can then be sent to the Building Control Officer and to our Energy Assessment team to complete the As built SAP/SBEM calculation and produce the Energy Performance Certificate

We pride ourselves on being:

  • Helpful –We work with you to achieve the best result, identifying potential issues and repeating the testing once these have been addressed. We are on hand to answer any questions before, during and after the testing.
  • Knowledgeable –All our test engineers have years of experience and have received the relevant training to allow them to carry out their job to the highest possible standards.
  • Flexible and Responsive –We issue quotes and certificates within one working day; our lead-times are typically around a week; however, we will try to accommodate where possible when tests are required by a certain date. We work around other on-site trades to minimise project disruption.
  • Great value –Our prices are very competitive. We can also undertake air and sound testing on the same visit to save you more money. If you do manage to find the testing cheaper, we will beat any quote.


To speak to our technical team about Air Tightness Testing for your project, please contact us on 01275 846995, or email info@cookbrownenergy.co.uk