Domestic Ventilation Commissioning

Professional Domestic Ventilation Testing & Commissioning

At Building Services Commissioning Ltd, we provide professional testing and commissioning services for domestic ventilation systems, helping ensure systems are operating correctly and meeting the requirements of the Building Regulations.

Effective commissioning is an essential part of the installation process. Our engineers test and adjust mechanical ventilation systems to ensure the required airflow rates are achieved and that the system operates as intended.

Our domestic ventilation commissioning services include:

• Mechanical ventilation airflow testing
• Testing and adjustment of ventilation systems
• Verification of designed airflow rates
• Commissioning of intermittent and continuous mechanical ventilation systems
• Completion of commissioning and airflow test documentation
• Provision of results for building control and project handover

Building Regulations Compliance

Domestic mechanical ventilation systems are subject to the requirements of Part F of the Building Regulations. Under Approved Document F, fixed mechanical ventilation systems must be commissioned by testing and adjusting the system as necessary to provide adequate ventilation.

For new dwellings, mechanical ventilation airflow rates must be measured and the results recorded and provided to the relevant building control body in accordance with the applicable requirements.

We carry out commissioning in accordance with the latest applicable Building Regulations, Approved Document F and relevant industry guidance, providing clear and accurate commissioning records on completion.

Where applicable, the interaction between ventilation performance and the energy-efficiency requirements of Part L is also considered as part of the commissioning process.

Suitable For Domestic Projects

Our domestic ventilation commissioning service can support a range of residential projects, including:

• New-build homes
• Residential developments
• Extensions and refurbishments
• Individual dwellings
• Apartments and residential developments
• Projects requiring independent ventilation testing and commissioning

Whether required as part of a new installation, project handover or compliance process, our experienced commissioning team can provide independent testing, adjustment and documentation to demonstrate ventilation performance.

Frequently Asked Questions

• Who is qualified to carry out domestic ventilation commissioning?

  The person carrying out the commissioning must either be a member of a registered Competent Person Scheme for ventilation, or provide suitable evidence to the building control body, alongside the commissioning sheet, demonstrating their competence.

• Is ventilation commissioning a legal requirement for new homes?

  Yes. Where a new dwelling is created, mechanical ventilation air flow rate testing must be carried out in accordance with a procedure approved by the Secretary of State, and notice of the results given to the building control authority. That notice must record the results and the data on which they are based, and must be given no later than five days after the final test is carried out.

• Which types of ventilation system need airflow testing?

  Testing applies to fixed mechanical ventilation, covering all four system types recognised in Approved Document F - intermittent extract fans, MEV, dMEV and MVHR. Where a new dwelling has a design air permeability of less than 5 m³/(h·m²) at 50 Pa, a continuous mechanical ventilation system is generally needed, as intermittent extract with background ventilators is not considered suitable at that level of airtightness. PIV is also not recognised as a compliant whole-house system for new dwellings, although it remains widely used in existing homes for condensation control.

• What test equipment do you use, and does it need to be calibrated?

  Air flow measurement must be carried out using equipment calibrated at a UKAS calibration centre. The model and serial number of each instrument used, together with the date of its last UKAS calibration, are recorded on the commissioning sheet. Our instruments are calibrated in date and certificates can be supplied on request.

• What happens if the measured airflow rates don't meet the design values?

  Compliance is achieved where measured rates are equal to or greater than the design value. If any measurement falls short, the system is adjusted and all air flows re-measured until the design values are met. Where adjustment alone cannot achieve the required rate, this is noted on the sheet, and remedial works may be needed to rectify the cause of the underperformance before the system is re-tested. We will always tell you clearly what is causing a shortfall rather than simply reporting a fail.

• When in the build programme should testing be booked?

  Testing should take place once the ventilation system is fully installed, ducted, powered and operating, with terminals and grilles fitted and the property reasonably clean. It needs to be complete before handover and in time for the results to be submitted to building control within the required period. Booking a slot in advance is sensible on phased developments, where we can attend in batches as plots are completed.

• What documentation is provided, and who needs a copy?

  We complete a full commissioning sheet recording the installation details, test equipment used and measured air flow rates against the design values, which is provided for submission to building control. A copy of the completed commissioning certificate should also be given to the building owner, together with the operating and maintenance information for the ventilation system.

• Do you test extensions, refurbishments and replacement systems?

  Yes. Approved Document F also covers material changes and replacement ventilation systems in existing buildings, where the principle is that any new or replacement system must not make ventilation provision worse. We regularly test individual dwellings and refurbishment projects as well as new-build developments.