Ventilation Testing and Commissioning

Building Regulations Part F - Ventilation

What is Extract Ventilation Testing and Commissioning?

Ventilation testing in dwellings includes checking trickle vents and testing extract fans to ensure compliance with 'Approved Document F of Building Regulations for England and Wales – Ventilation'.

Buildings are required to have some form of ventilation installed and these units can differ by system type, size and extract rate. Under Building Regulations Part F all extracts in a dwelling are required to be tested and must achieve a target extract rate.

The extract rates target for each extractor fan will depend on the room usage e.g. a bathroom will have a different target rate to a utility. It is important to achieve these targets to ensure the removal of water vapour and pollutants and to stop the formation of mould and the associated health problems.

Prior to the test, please ensure all trickle vents, extract fans and cooker hoods are installed and working correctly.

What is the best way to achieve compliance?

• Use the shortest possible ductwork path and prevent any blockage.
• The installation of appropriately powerful extracts.
• At least a 10mm undercut for each internal door.
• At least one trickle vent per window or two for double windows etc.

Are there minimum rates I need to achieve?

Yes. Depending on the location within the dwelling and the facilities the room has will affect the rate required. The most common ventilation system is System 1 - Intermittent Extracts and Background Ventilators. The targets for System 1 Extracts are:

• Utility - 30l/s
• Kitchen Cooker Hood - 30l/s
• Family Bathrooms and En-suites - 15l/s
• Sanitary Accommodation, W/Cs - 6l/s

Other ventilation systems of extract exist (System 3 -  and System 4) and also have their own targets to reach. The target for these systems is based not only on the room usage but also the number of bedrooms within the dwelling and the total floor area. System 1 is generally considered the simplest system to install and for compliance.

What should I do?

Before the test please ensure all trickle vents/extract fans and cooker hoods are installed and are working correctly. If the product is faulty this will make testing impossible.

Why is extract testing important?

As building regulations push for tighter requirements regarding carbon emissions and primary energy demand, buildings are being built with lower air tightness test scores. This puts a greater importance on ensuring the correctly sized purpose ventilation systems are installed and once installed, the ventilation system is operating effectively. For example, if extractor fans are placed within rooms where water vapour or pollutants are released it is important to remove them and stop the spread to the remaining house as long-term impacts could be dampness or mould which both affect a person’s health.

Our assessors can work to ensure extract testing is as and quick and simple as possible. Extract testing is requirement for building regulations compliance. Give us a ring, or fill out the contact form below to book your extracts in for testing.