Welcome to ENPRO UK

Acoustic Air Tightness Testing Services

Serving Newcastle, Sunderland, County Durham, the Tees Valley and North Yorkshire

Enpro provide on-site air tightness testing throughout the UK on both commercial and residential buildings. We also offer a free consultancy at design stage, or a one-off pre-test visit to highlight problem areas.

Air tightness is the key feature of any energy efficient building; by reducing wasted heat and allows the buildings atmosphere to be controlled with mechanical ventilation heat recovery units creating a healthier environment.

Air-tightness testing is undertaken to determine a buildings air-permeability rating. Air tightness testing is an integral part of Part L of The Building Regulations which requires new buildings to meet specific air-permeability targets.

Achieving improved air tightness is a key factor in building contractors meeting the government’s target for reduced carbon emissions and improved energy efficiency.

What is an Air Permeability Test?

Air permeability testing, also known as air leakage testing establishes the rate at which air leaks out of a building when all windows, doors and extractors are closed. The higher the air leakage, the more heating the building may require. Therefore, the building may have substantial energy consumption and CO2 emissions, high heating bills and occupant discomfort.

  • In response to the EPBD: as of 4th January, 2009 all commercial property for sale or let now requires a commercial EPC (Energy Performance Certificate).
  • The commercial EPC will tell you how energy efficient the commercial property is on a scale of A-G, with A being the most efficient. The certificate also tells you, on a scale of A-G, about the impact the property has on the environment.
  • It is now mandatory that a commercial EPC is in place prior to marketing a commercial property.
  • An EPC is legally required to market a commercial property.
  • Newly constructed commercial buildings are also required to have an EPC.
  • The commercial EPC is combined with a recommendation report on how the property’s energy efficiency can be improved, in addition to a potential rating if the recommendation work is carried out.
  • Commercial EPC’s are valid for a 10 year period.

Under current commercial EPC legislation, a commercial EPC is not required on the following exempt premises:

  • On lease renewals or extensions in place prior to 1st October, 2008.
  • Places of worship.
  • Stand-alone buildings less than 50 square metres.
  • Properties with consent to be demolished within the 2 year period

Non-compliance with commercial EPC legislation will result in a penalty. The penalty is of up to 12.5% of the rateable value of the property, with the minimum of £500 and a maximum of £5,000. This is in addition to the cost of a compliant commercial EPC.

Carrying out the Test

A high precision fan is set up on one of the external doors and used to extract air from the building to create a pressure differential. Pressure readings are taken and used to be measure the amount of air that leaks into the building per hour. The building envelope area is calculated by calculating the areas of the external walls, roof and floor of the building. This is then used to find the air permeability in m3 per hour per m2 of building area.

The limit is set by the regulations should be easily achievable for most modern buildings and represents an air change rate of about 10 per hour, but the limit set in your SAP calculations is likely to be lower than 10.


If your site fails an air test, we won’t walk away. We’ll talk to you and your management team and offer advice on what you need to do to gain your EPC. Usually with input from one of our experienced engineers we can resolve the problem on the day.

Short Notice Requests

Get in touch with one of our experienced members of our team at Enpro UK, and we will always aim to get to you as soon as possible. With notice, we can also test at weekends if needed. There will be an extra charge for this service.

For further information, quotes or to book an air test, please contact us below.