Ventilation flow rate testing for new-builds, conversions and extensions.
At Barlings KWA, we provide Part F extractor fan testing for new-build dwellings, extensions, conversions and refurbished properties requiring ventilation evidence for Building Control.
Extractor fans and mechanical ventilation systems are an important part of Building Regulations compliance. Under Approved Document F, ventilation should be provided to help maintain indoor air quality and remove moisture from areas such as kitchens, bathrooms, utility rooms and WCs. Approved Document F Volume 1 applies to dwellings in England, with updated 2026 guidance available for projects subject to the 2026 standards. Earlier versions may still apply depending on the project’s Building Regulations application date.
Whether you are a builder, developer, homeowner or architect, we can test the installed ventilation rates and provide a clear report for submission to Building Control.
Email: [email protected] or [email protected]
Domestic & commercial testing
Lincolnshire based
UKAS-calibrated equipment
Certification within 24 hours
What is Part F extractor fan testing?
Part F extractor fan testing, also known as ventilation flow rate testing, checks whether installed extractor fans are achieving the required airflow rates.
Testing is usually carried out using calibrated airflow measurement equipment to record the extract rate from each fan or terminal, normally measured in litres per second.
Typical areas requiring extract ventilation include:
- Kitchens
- Bathrooms
- Shower rooms
- Utility rooms
- WCs / sanitary accommodation
The aim is to confirm that the installed system is performing correctly, rather than simply relying on the fan manufacturer’s stated performance.
Why is extractor fan testing needed?
Extractor fans may not achieve their expected airflow once installed. Performance can be affected by:
- Long duct runs
- Flexible ducting
- Crushed or restricted ductwork
- Too many bends
- Poor external grille selection
- Incorrect fan settings
- Incorrect fan settings
- Lack of commissioning
- Blocked or poorly fitted terminals
A fan may appear to be working, but still fail to provide the correct ventilation rate. Testing helps identify these issues before completion, allowing any remedial work to be carried out before Building Control sign-off.
What our clients say
We have recommended Barlings KWA to many of our clients for their air testing and energy assessment services. William and Kerry are extremely helpful and always deliver the work accurately and on time
Joe Campion
When should testing be carried out?
Extractor fan testing is normally carried out near completion, once the ventilation system is fully installed and operational.
Ideally, the following should be in place before we attend:
- Extractor fans fitted and powered
- Internal grilles or terminals installed
- External vents fitted
- Ductwork complete
- Fan boost settings available where applicable
- Access available to all rooms requiring testing
For new dwellings, ventilation evidence is often required alongside other completion documents such as air test certificates, SAP reports and EPC evidence.
Why choose Barlings KWA Ltd?
Barlings KWA Ltd is a Lincolnshire-based energy-assessment and building-compliance company providing air tightness testing for domestic and commercial projects. Since 2007, we have supported builders, developers, architects and homeowners with practical advice, clear communication and prompt certification.
- Air tightness testing experience since 2007
- Domestic, commercial and larger-building experience
- UKAS-calibrated equipment
- Drawing reviews and pre-test advice available
- Direct contact with the person carrying out the test
- SAP, SBEM, EPC and other compliance services available
Common reasons extractor fans fail
Some of the most common problems we find are:
- Flexible ducting crushed in the roof space
- Excessively long duct runs
- Ducts with tight bends
- External terminals restricting airflow
- Fans not set to the correct boost speed
- Incorrect fan type for the duct length
- Backdraft shutters causing resistance
- Poor installation despite a suitable fan being specified
Testing before final handover can avoid delays with Building Control and reduce the risk of condensation or indoor air quality issues later.
More client feedback
“Always happy to answer any queries we have; the service and information they provide is excellent.”
— Kirsty Uttley
“A fantastic, professional company to work with. Great communication and turnaround time.”
— Chris Henderson
Who needs Part F extractor fan testing?
Our service is suitable for:
- Builders
- Developers
- Architects
- Homeowners
- SAP assessors
- Building control applicants
- Contractors completing new dwellings or extensions
We regularly assist with Building Regulations compliance evidence and can work alongside your SAP, EPC, air testing and other completion requirements.
Book a Part F extractor fan test
If you need Part F extractor fan testing for a new-build dwelling, extension, conversion or refurbishment, please contact Barlings KWA Ltd.
We can confirm what information is required, arrange a suitable test date and provide a report for Building Control.
Contact Barlings KWA today to arrange your ventilation flow rate testing.