Air Testing

Air Tightness Testing

Operating throughout the UK, Stroma Built Environment has delivered Air Tightness Testing on more than 100,000 buildings, including dwellings, office buildings, educational establishments, hospitals, superstores, factories and warehouses. We are a UKAS accredited testing laboratory and our on site technicians work closely with architects, project managers, quantity surveyors and design managers to help you take the stress out of air testing.

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Air Testing Literature

A Nationwide Team of Air Testing Engineers

Meet one of our ATTMA Level 1 and Level 2 Air Tightness Engineers working on projects within your region. You can book your Air Test today or speak to one of your regional representatives regarding your Air Tightness requirements.

Find one of your local Air Testing Engineers in your local area by clicking on the map.

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air tightness tests completed annually


Level 1 and Level 2 qualified engineers


buildings air tested across the world


daily air tests carried out on site

Air Testing Service

Air Testing Service

Your Stroma engineer will work alongside your on site team to carry out the Air Tightness Test efficiently and with minimal disruption to other site activities. A UKAS calibrated fan or number of fans is placed within the building envelope in order to carry out a pressurised or depressurised test. Our standard process can be described as follows:

  • Pre-Test Inspections / Audit: Visits to site throughout construction to ensure effective implementation of the agreed air barrier strategy. All observations are conveyed in a detailed, illustrated report
  • Initial Air Tightness Testing: An initial air tightness test is carried out on a sample area to give an indication of how the whole building will perform and the key air leakage issues
  • Final Acceptance and Air Leakage Testing: Once the final stages of construction have been finalised and any pre-inspections fulfilled, a final test is required to demonstrate compliance against Part L. The final test includes all necessary building envelope calculations and is carried out using multi-point Air Pressure Testing methods to ensure an even pressure distribution, and thus, reliable results. In large complex buildings, this approach, along with our ability to depressurise the building, can be vitally important
  • Post-Test Leakage Diagnosis: If a building fails to achieve the required air permeability rating, Stroma’s technicians will carry out smoke testing methods to identify any air leakage and advise on any remedial works in an illustrated report.
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What is Air Testing?

Air Testing (also known as Air Pressure Testing or Air Tightness Testing) is a requirement of the Building Regulations. Part L states that new developments must meet specific air permeability targets to minimise the risk of heat loss and energy inefficiency caused by air leakage. Stroma Built Environment has the world’s largest team of experienced Level 1 and Level 2 Air Tightness Technicians to carry out Air Pressure Testing. Our comprehensive Air Testing services help our clients to determine the development’s air permeability rating so you can meet your carbon reduction and sustainability targets and improve occupier comfort.

The benefits to having an air tight residential property include:

  • Reduced costs to heat the property
  • Reduced carbon emissions
  • Improved occupier comfort levels

Air Tightness Testing should be undertaken when buildings are virtually complete (usually in RIBA stages 5 and 6) and under calm weather conditions. Depending on the size, complexity and height of the building, either large trailer-mounted fans or smaller electric ‘blower-door-fans’ are used to undertake the air tightness tests to determine any air leakage. Stroma can design and deliver a bespoke service package combining all, or a combination of our Air Tightness and Air Pressure Testing services to facilitate compliance with Part L 2013.

We can help you meet Part L of the Building Regulations and its stringent requirements to reduce CO2 emissions. Part L 2013 currently requires an overall 6% reduction in CO2 emissions and we can help you achieve this through focussed attention on your air barrier strategy and recommendation of a variety of carbon reduction measures.

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What is Air Testing?

Commercial Air Testing

Commercial Air Testing

Part L2A of the Building Regulations requires every commercial building to undergo Air Tightness Testing and achieve a test result of 10m3/hr2 or less. Stroma Built Environment can provide the necessary Air Permeability and Air Pressure Testing for your commercial or mixed use developments to determine the air leakage and air permeability. Our consultants will work with you from the earliest stages of your commercial development, providing relevant advice and complementary services, such as necessary SBEM Calculations to help your building reach its air tightness targets. We approach Commercial Air Testing projects with a large multi-fan testing system to support accurate collection of air leakage data.

Stroma Built Environment is one of the world’s foremost experts in commercial testing and our engineers have undertaken projects across the globe, including in Asia and South America. Our experience in commercial buildings includes:

  • Retail units (inc. supermarkets)
  • Offices
  • Education buildings (inc. schools)
  • Hospitals and Health facilities
  • Industrial units (inc. warehouses)
  • Leisure facilities (inc. sports centres)

For non-domestic air tests, our engineers work closely with colleagues in our Energy department to analyse air leakage targets against the requirements of an SBEM Calculation. Engaging Stroma Built Environment means you can rely on coordinated and efficient support from our Air Tightness Engineers and SBEM Assessors as part of your Part L compliance requirements.

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Residential Air Testing

The Building Regulations require all new build and existing dwellings to pass an Air Test. Stroma Built Environment offers domestic Air Tightness and Air Pressure Testing on all residential buildings to ensure your developments meet their efficiency targets and offer optimum comfort for the occupants. We work with you from an early design stage, offering expert advice and mitigation measures to support your projects in passing our domestic Air Tightness Test the first time. Our clients include major residential housebuilders on multi-plot developments to single plot private residential work. By employing the industry’s largest team of L1 and L2 qualified test engineers we can deliver a flexible and adaptable approach to testing your residential plots.

Clients for Domestic Air Testing tend to also engage our SAP Assessment team to deliver SAP Calculations as part of a Part L compliance pack. Our one plot offer for New Build Certification to Part L, F and G of the Building Regulations starts from only £599 and covers:

  • Air Test
  • SAP Calculation
  • EPC Certification
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Residential Air Testing

Management Information for your project

Management Information for your project

Stroma Built Environment has in-house capability to deliver management information and data about a site and project throughout the Pre-Construction phase, into Construction and to support building management Post Completion. Clients can access a web based MI dashboard to view real time information about your projects, including:

  • Volume of engineer visits by month
  • Volume of air tests by outcome
  • Pass/Fail statistics per plot
  • Regional testing statistics

Our unique capability to deploy environmental sustainability services throughout the RIBA Plan of Work couple with our data analysis service allows Stroma Built Environment to deliver a holistic compliance package to our Air Testing clients.

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