Ventilation Testing

Part F of the Building Regulations 2010 provides the legal requirements and guidance for ventilation in new and existing buildings in the UK. The regulations are in place to ensure good indoor air quality for occupants, and to prevent issues like condensation and black mould.

As buildings become more airtight to improve energy efficiency, proper ventilation is crucial. Without it, moisture and pollutants can build up inside, leading to poor air quality, condensation, and black mould, which can be harmful to both the building and the health of the people living in it. Ventilation testing is a legal requirement for all new build properties to ensure the installed ventilation systems are performing correctly.

Yes, if you have a new build domestic or non-domestic property, you will need to have the ventilation system tested to comply with Part F of the Building Regulations. This is usually requested by your building control body before the property can be signed off. Testing is not required for storage spaces, or garages attached to a single home.

A certified engineer will use a piece of equipment called a balometer to measure the airflow rate at each extract vent in the property (e.g., in kitchens and bathrooms). The process is quick, and the results are available almost instantly.

Unfortunately, a high percentage of ventilation systems (around 60-70%) fail the test on the first attempt. If this happens, you will need to either fix issues with the ducting and installation, or replace the extractor fans with more powerful units. After the remedial work is done, a re-test will be required, which will incur additional costs.

The most common reasons for failure are poor ductwork design and installation. To give yourself the best chance of passing first time:

1. Avoid kinks and squashing flexible ducting. Ensure the ducting has a clear, straight run.

2. Keep ducting runs short. Any duct run over 1.5 metres will significantly reduce the performance of standard axial fans.

3. Use more powerful fans for longer duct runs. If you can’t duct directly through a wall, consider using more powerful centrifugal or inline fans.

While both are important for a healthy and energy-efficient home, they focus on different things. Part L is concerned with limiting heat loss and making the building airtight. Part F, on the other hand, is about ensuring that, despite this airtightness, there is still enough fresh air coming into the building. The more airtight a building is, the more important a properly designed and installed ventilation system becomes.

While natural ventilation (opening windows) is encouraged, mechanical ventilation is often necessary in the following situations:

– Highly insulated and airtight buildings: These properties can struggle with natural airflow, so mechanical systems are needed to bring in fresh air.

– Locations with poor outdoor air quality: If the property is near a busy road or industrial area, a mechanical system can filter the incoming air.

– Properties with limited window openings: In these cases, a mechanical system can ensure adequate ventilation.

Ventilation testing is a requirement under part F of the building regulations for all new property developments and is normally carried out right at the end of the project, just before residents move in.  All new build dwellings require a Part F ventilation test for building control.

Mechanical Ventilation with Heat Recovery (MVHR) systems are increasingly being used in energy-efficient buildings as they can be calibrated to use very little electricity. This calibration, called MVHR commissioning, needs to be carried out by an experienced air tester.

MVHR commissioning involves testing and adjusting the fan speed in each fan unit to optimise its performance. Fan flow rates need to be recorded before the system can be certified.

While ventilation testing is mandatory for new builds, it can also be beneficial for existing properties. We can assess your existing ventilation system and identify areas for improvement. This can help you:

– Improve indoor air quality and reduce the risk of mould growth.

– Increase energy efficiency by ensuring your existing ventilation system is functioning properly.

– Create a more comfortable and healthy living environment.