Extract Flow Testing

Extract Flow Testing

Extract Flow Testing or Ventilation Testing has been a mandatory part of building regulations since 2010. It is essential that all new builds conduct a test to ensure compliance with Part F of the Building Regulations. 

What is Extract Flow Testing?

An extract flow test measures air flow rates of mechanical ventilation systems (such as extractor fans/oven hoods) installed in new properties. Part F of building regulations is concerned with reducing the amount of uncontrolled airflow throughout a property and therefore increasing its overall air tightness. 

Why is it important?

All new builds must meet the minimum standards set by Building Regulations, making an extract flow test a crucial step in the planning process. As buildings are becoming more insulated and air tight it is essential that appropriate ventilation systems are in place in order to maintain airflow throughout the property. 

Extract units are typically placed in rooms where air moisture and pollutants are released (kitchens and bathrooms etc), in order to prevent mould and dampness which may impact on occupants' health. 

What does an Extract Flow Test involve?

The test is relatively straightforward and can be carried out alongside an air tightness test (also required). The inspection will cover the following areas:

  • Extractor fans: are they suitably fitted and functioning correctly?
  • Checking background ventilators are installed and in an open position
  • All windows and doors are correctly fitted and sealed. 
  • All internal doors have 10mm over and above the final floor finish, in order to allow air flow between rooms. 

When should I carry out the test?

It is generally more cost effective to carry out an extract flow test alongside an air tightness test, the timing of which will vary depending on the property type.

For single units, an air tightness test should be conducted at the end of construction, before final approval is given. If your project involves multiple units then testing should be carried out during the construction of the first 25% of the dwelling type. 

How do I arrange a Test?

We highly recommend that you get in touch with us first. Our expert energy consultants can then advise you on the compliance requirements for your specific property/ properties. 

An Extract Flow Test is carried out on site and is therefore not conducted by Elmhurst Energy Services. Our consultants take the results from the test in order to incorporate them into the final SAP or SBEM calculation, however we can recommend trusted third party assessors to carry out the test. 

Call us now on

01455 883 259

 and discuss your project with us, there’s no obligation and we’re happy to advise you.

Or why not complete our 'Get a quote' form




Related Links

Air Tightness Testing >Air Tightness Testing for Dwellings  > Air Tightness Testing for Commercial Buildings >

Get a quote

Please provide a few details below and we'll get back to you as quickly as possible


Elmhurst Energy Services Ltd. 16, St Johns Business Park, Lutterworth, Leicestershire, LE17 4HB

© Elmhurst Energy Services Ltd 2022. All rights reserved. Elmhurst Energy Services Limited is registered in England, Company Number: 06087105