Commercial Air Tightness Testing

We provide competitively priced commercial air tightness tests and consultancy services for all types of commercial developments including simple retail units, offices, industrial buildings, leisure facilities and care homes.

We also provide a number of ancillary services to supplement our Commercial Air Tightness Testing including Design Reviews, Pre-Air Test Visits & Inspections, Diagnostic Smoke Testing and Diagnostic Thermal Imaging.

EPS Group: Expert Air Tightness Testing and Consultancy for Commercial Buildings?

Air Tightness Testing (also referred to as Air Pressure Testing or Air Leakage Testing) is a method for measuring the amount of conditioned air that is unintentionally lost from the inside of a building as a result of unsealed gaps or cracks within the thermal envelope of the property (also known as air leakage or air infiltration. The graphic below highlights a number of common sources of air infiltration within a commercial building.

Each commercial air pressure test is completed by an accredited Air Tightness Contractor in strict accordance with a standardised methodology detailed within the Technical Guideline ATTMA TSL2 Measuring Air Permeability of Building Envelopes (Non-Dwellings).

For more information relating to Commercial Air Pressure Testing please explore the Frequently Asked Questions below.

Alternatively, to discuss your Air Tightness Testing requirements further, please contact us on 0115 7270599 email us at, or complete our enquiry form.

Why is Air Tightness Testing required in Non-Domestic Properties?

Asides from causing potential discomfort to occupiers, excessive air leakage increases the energy demand of building owing to the uncontrolled loss of conditioned air from the building (heated or cooled). As well as increasing the running costs of the property excessive air leakage results in additional carbon dioxide (CO2) emissions arising from the building.

As part of the Government’s drive for improving the energy efficiency of buildings and reducing the overall carbon dioxide emissions from the built environment, Air Tightness Testing was introduced to Approved Document Part L2A of the Building Regulations in 2006 (as applicable to newly built commercial properties).

In addition to the standard requirements of the Building Regulations, many tenants and building owners also stipulate maximum Air Permeability Rates within their build specifications and contract conditions in order to ensure that they will have an energy efficient building with reduced running costs on completion.

Improved Air Pressure Test results can also help the building achieve credits in environmental or sustainability certification schemes such as BREEAM or help with increasing the EPC Asset Rating of the building.

Common Sources of Air Infiltration in Non-Domestic Properties

Commercial Air Tightness Testing FAQs

What Air Permeability Rate is required to pass a Commercial Air Pressure Test?

Approved Document Part L2A of the Building Regulations allows for a maximum air permeability rate of 10.00 m3.h/m2 per tested commercial building. This relatively generous air leakage rate is a maximum ‘backstop’ value which is often superseded by a lower ‘target’ rate detailed within the building’s Design Stage SBEM Calculation and BRUKL document. In order to help the SBEM calculation to pass to carbon emission requirements of Part L2A of the Building Regulations, it is common for commercial developments to have to achieve a measured air permeability rate of 5.00 m3.h/m2 or less.

Do all new commercial buildings require an Air Tightness Testing?

Approved Document Part L2A of the Building Regulations has a mandatory requirement for all new commercial buildings with a floor area greater than 500m2 to have an Air Leakage Test. Smaller commercial buildings are permitted to avoid an Air Pressure Test provided the SBEM Assessment for the unit still shows an overall pass when a penalty Air Permeability Rate of 15.00 m3.h/m2 is applied. As a consequence, it tends to be far more economical to commission a ‘voluntary’ commercial pressure test to help the SBEM Calculations to pass rather than undertaking costly compensatory measures.

How Do I Pass an Air Tightness Test?

In order to have the best chance of passing an Air Tightness Test, we would recommend reviewing our illustration showing common areas of air infiltration within commercial buildings. It is important that these potential sources of air leakage are well sealed before any air tightness test is scheduled.

We would also advise adhering to the following key principles throughout the development process in order to help achieve a low air permeability: 

  • Identify the air barrier within the proposed building at an early stage of design
  • Refer to airtightness in all contracts which may impact the integrity of the air barrier during construction
  • Highlight the importance of the air tightness barrier to project teams
  • Select airtight components
  • Check interfaces between components
  • Ensure all site workers are aware of the importance of maintaining the integrity of air barrier
  • Complete regular checks on the air barrier throughout construction
  • Ensure that all works are complete prior to the final test


How can EPS Group help with Commercial Air Tightness Testing?

There are many reasons to appoint EPS Group to provide your Commercial Air Tightness Testing

How can EPS Group help with Commercial Air Tightness Testing?

Since 2007, EPS Group has been providing professional and efficient Air Tightness Testing for all types of non-domestic buildings throughout England and Wales. We are also vastly experienced with pressure testing domestic properties meaning that we are also well placed to complete the air pressure tests on all types of development.

As part of our client-focused service, we allocate a reasonable amount of time within our appointments to allow our client’s the opportunity to undertake any permanent remedial works that may be identified during the air pressure test procedure. This provides the best possible chance of achieving a pass certificate for the commissioned Air Tightness Test.

We also provide the following ancillary services to support the air leakage testing of commercial buildings:


Design / Plan Reviews


Mid build and pre-test site inspections


Mid build air tightness tests


Whole building smoke diagnostics


Thermally imaging diagnostics


Pre and post improvement testing

Our Air Tightness Technicians work from the same offices as our SAP and SBEM Assessors which can provide significant time savings when we are instructed to provide a full Part L compliance package.

EPS Group: A Partner for those in the Construction Industry

We value the importance of a solid working relationship with those in the construction industry, and for many, we serve as the reliable go-to-company to entrust from the planning stage of a development through to completion.

What Our Clients say:

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Let’s discuss your Commercial Air Tightness Testing project!

Jual Ahmed
Jual Ahmed
Excellent service from start to finish. I would highly recommend and will definitely use again. Thank you!
A great service and attended within a week of request. Polite knowledgeable engineer who completed the test quickly and efficiently...Thank you EPS
Steve Naylor
Steve Naylor
EPS group undertook the initial SAP design assessment, then the as-built assessment for my new property, including air test. They were super-responsive and made the appointment for the air-test within a few days of the request. The certificates were issued very promptly and they helped me through the process (I had never done this before). Really recommend them.
Nick Collingridge
Nick Collingridge
Great service from EPS Group. Their operative was friendly, efficient and very helpful. He carried out his survey quickly and then spent time walking round the property with me pointing out all the points at which air was infiltrating. He also passed on some invaluable tips about the best way to attend to the detailing of aspects of a property's structure to maximise air tightness. I am altogether very satisfied with the survey.
Mark Blood
Mark Blood
Have worked with EPS for several years now in connection with all of our energy assessment requirements. Extremely efficient service at very competitive fees and always available to offer advice on achieving compliance. Would definitely recommend.