Elmhurst Energy has reported that the recent Future Homes Standard consultation in England proposed several key changes to Part F of the Building Regulations, covering ventilation testing equipment, the scope of air flow testing and who may commission mechanical ventilation systems. The body published its summary on 13 August 2024.
Under the proposals, rotating vane anemometers would not be permitted for testing continuous mechanical ventilation systems. For these systems, only powered flow hoods would be allowed, and they would have to be calibrated annually1. Elmhurst states this would improve the accuracy of measurements but would come at an additional cost to the individual performing the commissioning1.
A second proposal would extend Building Regulation 42, which covers air flow testing, to the installation of mechanical ventilation in existing homes. At present this applies only to installations in new homes1. Elmhurst notes that energy efficiency measures in existing homes increasingly require additional ventilation to be installed, and that the procedures for commissioning mechanical ventilation would be extended to cover new systems installed in existing homes1.
A third proposal concerns who may carry out commissioning. It is proposed that commissioning should only be completed by members of a Competent Persons Scheme or the Building Control Body1. Elmhurst states that the Building Safety Regulator is now responsible for Competent Person Schemes, and that these are expected to play a greater role in demonstrating compliance with Building Regulations in future1.
"Elmhurst is aware that compliance with this area of the Building Regulations is poor. We therefore support the move to use competent people to complete this crucial service."
Elmhurst operates a Ventilation Competency Scheme for individuals who commission ventilation systems1. The rules differ by nation: in England and Wales ventilation is covered by Part F of the Building Regulations, in Scotland by Section 3 of the Building Standards Technical Handbook, and in Northern Ireland by Technical Booklet K1. Elmhurst states that the other devolved administrations are expected to make proposals for the installation of ventilation systems in consultations to their Building Regulations or Standards later this year1.
Why it matters for households
Ventilation sits alongside insulation and airtightness in determining how a home performs. Elmhurst states that poorly operating ventilation systems can result in high levels of pollutants and damp and condensation, with a direct impact on occupants' health, and can also cause systems to run inefficiently, leading to increased carbon emissions and higher fuel bills1. As homes become more energy efficient, the interaction between airtightness and controlled ventilation becomes more significant, which is the context for tighter testing and commissioning rules. The proposal to extend air flow testing to existing homes would bring mechanical ventilation installed during retrofit work within the same commissioning procedures as new-build installations, a change relevant to households having ventilation fitted as part of energy efficiency improvements. The restriction of commissioning to Competent Persons Scheme members or the Building Control Body would change who is recognised as able to sign off that work. The consultation itself is a proposal, not a decision, and the outcome for Part F has not been reported.
What happens next
Elmhurst states that the other devolved administrations are expected to make proposals for the installation of ventilation systems in consultations to their Building Regulations or Standards later this year1. No dates for a government response to the Future Homes Standard consultation, or for implementation of the Part F proposals, are given in the source.
Sources1 cited
- The importance of ventilation in homes - Elmhurst Energy, elmhurstenergy.co.uk