top of page

Background Ventilation Testing

We provide Background Ventilation Testing for contractors, house builders, social landlords and local authorities across the UK. Our field-based service helps demonstrate whether a property already has sufficient natural ventilation, supporting healthier indoor air quality and energy-efficient retrofit decisions. The service is PAS 2035 compliant and TrustMark approved, giving you confidence that your project data is accurate and professionally assessed.

By evidencing existing background ventilation, you may be able to avoid unnecessary additions such as trickle vents or door undercuts where adequate ventilation is already present. We offer a professional service alongside Airtightness Testing, delivered by a qualified team working to recognised industry standards.

mini bd.jpg

Background Ventilation Testing

Professional Assessments

​​Benefits of Background Ventilation Testing

  • Demonstrates compliance with PAS 2035 requirements.

  • Helps avoid unnecessary ventilation upgrades and reduce project costs.

  • Suitable for houses, flats and bungalows.

  • Supports smooth project delivery with quick, reliable results.

  • Can often include pre- and post-installation testing on the same day.

  • Volume-based pricing is available on request.

 

Pre- and Post-Installation Testing

For retrofit projects, we can carry out background ventilation testing before and after Energy Efficiency Measures are installed. This helps confirm that ventilation remains appropriate once improvements have been made.

 

Pre-installation

A test is first carried out on the dwelling as it stands. This establishes the existing background ventilation level and helps identify whether additional measures may be needed to meet PAS 2035 guidance.

 

Post-installation

Once the planned Energy Efficiency Measures have been completed, a second test can be carried out to confirm the final ventilation performance. In many cases, both tests can be completed on the same day, including for cavity wall insulation, loft insulation or underfloor insulation projects.

 

Background Ventilation Testing vs Airtightness Testing

Although the same equipment may be used for both, Background Ventilation Testing and Airtightness Testing are not the same.

Background Ventilation Testing measures whether a building has enough existing ventilation. It is used to assess indoor air movement and confirm that the property is adequately ventilated.

Airtightness Testing measures how much uncontrolled air leaks out of a building. This is used to assess energy performance, heat loss and compliance with building regulations.

In simple terms, background ventilation testing looks at whether there is enough air movement, while airtightness testing looks at how much air is escaping.

 

How the test is measured

Background Ventilation Testing measures the air change rate, usually expressed as air changes per hour (ACH). This shows how many times the full volume of air in a room or dwelling is replaced in one hour.

For this type of test, existing ventilation is closed or switched off, but not sealed. This allows us to assess the property’s natural background ventilation under normal conditions.

 

What it means for PAS 2035

Our background ventilation testing can be used to support compliance with PAS 2035 by evidencing whether a property has adequate ventilation in place. This helps inform retrofit decisions and reduces the risk of over-specifying additional measures.

 

What it means for residents

The testing process is quick, straightforward and low-disruption for occupants. Our team can work with residents to arrange appointments at convenient times and explain the process clearly in advance.

The test is safe for children and pets, and our testers are happy to answer any questions before, during or after the visit.

 

Who benefits?

  • Homeowners and residents gain reassurance that their property has sufficient ventilation, helping reduce the risk of condensation, damp and mould.

  • Installers, coordinators and designers receive the data they need to choose the right next steps for the property.

  • Housing associations and social landlords gain a clearer understanding of stock condition and where ventilation improvements may be needed.

 

Need help choosing the right test?

Our experienced team can help you decide whether Background Ventilation Testing, Airtightness Testing or a combination of both is right for your retrofit project.

bottom of page