Domestic Extractor Fan Testing
Domestic Extractor Fan Testing & APT
As part of the evolving UK Building Regulations, Part F (Ventilation) now mandates that all intermittent extractor fans — such as those installed in kitchens and bathrooms — must have their airflow rates tested on-site. These results must be submitted to the local Building Control Body (BCB) before the property can be signed off and handed over.
At APT Sound Testing, we specialise in helping developers, contractors, and homeowners ensure full compliance with these updated regulations. With our UKAS accreditation and expert team of consultants, we offer efficient, cost-effective extractor fan testing, often conducted at the same time as your air and acoustic testing, to save time and reduce project coordination challenges.
Why Extractor Fan Testing Is Now Essential
As energy efficiency standards tighten, new buildings are becoming increasingly airtight and insulated. While this is great for reducing heat loss, it also places more demand on mechanical ventilation systems to ensure good indoor air quality. Poor ventilation can lead to moisture buildup, damp, mould growth, and even health issues for occupants.
To address this, Approved Document F outlines strict requirements for Mechanical Ventilation and Heat Recovery (MVHR) systems, as well as intermittent extractor fans. These systems must be tested, commissioned, and certified before a building can be signed off.
This makes extractor fan testing not only a compliance requirement—but a crucial part of ensuring occupant comfort and well-being.
Types of Ventilation Systems Under Part F
Approved Document F defines four types of ventilation systems, known as Systems 1 to 4. Here’s a quick breakdown:
System 1: Background Ventilators + Intermittent Extract Fans
This is the most commonly used approach. Moisture and odours are extracted via fans in wet areas (e.g. kitchens, bathrooms), while fresh air is introduced through trickle vents or background ventilators in windows or walls.
System 2: Passive Stack Ventilation (PSV)
This uses natural airflow driven by wind and temperature differences. It includes roof-level outlets and background ventilators—ideal for energy-conscious homes but harder to control.
System 3: Continuous Mechanical Extract Ventilation (MEV)
MEV systems continuously remove air from wet rooms using mechanical fans, usually ducted to one central point. Fresh air enters via trickle vents.
System 4: Mechanical Ventilation with Heat Recovery (MVHR)
MVHR systems provide both supply and extract ventilation through ducts, while also recovering heat from the outgoing air. This is the most energy-efficient system but requires careful design and installation.
Not sure which system is right for your property? Contact our experienced team to talk through your project needs and compliance strategy.
Required Extract Rates for Domestic Fans
Approved Document F outlines the minimum airflow rates that each extractor fan must achieve, regardless of property size or type:
- Kitchens (cooker hood or similar): 30 litres per second (l/s)
- Bathrooms (intermittent fans): 15 l/s
- WCs (sanitary accommodation): 6 l/s
These rates must be verified on-site using calibrated equipment. Failure to meet the required airflow levels can delay handover and lead to additional remedial costs.
When and How We Test
In most cases, our team can carry out Ventilation Flow Rate Testing during the same visit as your Air Tightness Test. This means you can achieve Part L and Part F compliance simultaneously, saving valuable time and project costs.
Our engineers are trained to work efficiently and respectfully on active construction sites, ensuring minimal disruption and rapid turnaround of test results.
Pre-Test Checklist: Preparing for Extractor Fan Testing
To ensure a smooth testing process, the following elements should be complete before we arrive on site:
- Electrical supply connected to all extractor fans.
- Fans must be fully installed and operational.
- Surrounding finishes (e.g., plasterboard/masonry) must be sealed properly to ensure airtightness.
- All windows and external doors must be installed.
- Trickle vents fitted to all applicable windows.
- Safe access must be available to all test points (both internal and external).
- SAP calculation worksheets must be provided for each unit.
- All internal doors installed.
- Ventilation specifications for each fan type must be supplied.
- Floor plans and sections must be submitted at least 3 working days in advance.
- Occupancy schedule indicating the number of residents per unit.
- Parking space provided within 50m of the building.
- The building envelope must be complete—doors, windows, cladding installed.
- Interior finishes complete, including switches, sockets, flooring, and ceiling surfaces.
Need help reviewing your site readiness? We’re here to guide you through the process.
Why Choose APT Sound Testing?
APT Sound Testing are a UKAS-accredited laboratory, meaning our testing and reporting meet the highest standards of accuracy and reliability under ISO certification. With years of experience in acoustic design and building compliance, we’ve worked on thousands of projects, from single dwellings to large residential developments.
Our clients return to us time and again because we offer:
- Fast, efficient service
- Expert consultancy
- Combined testing packages (air, sound, vent)
- Reliable certification for building control
- Friendly, knowledgeable support
We understand that compliance isn’t just about ticking boxes, it’s about delivering healthier, more comfortable homes. That’s why we take the time to understand your project’s unique needs and offer tailored solutions every time.
Get in Touch Today
Our team is ready to help you meet your Extractor Fan Testing and ventilation compliance obligations with ease and confidence. Whether you’re planning a new build or preparing for completion, we’ll ensure your extractor fan systems are correctly tested, certified, and fully compliant with Approved Document F.
Call us today on 01525 303905 or use our contact form on our website to speak with one of our expert consultants about your project. We’re here to help you every step of the way.