Ventilation rules set for tighter scrutiny under 2027 building standards

17 July 2026

Housebuilders and housing providers in England and Wales will face stricter requirements on the design, installation and certification of ventilation systems when updated Building Regulations take effect in 2027.

The changes form part of the Future Homes and Buildings Standards, which aim to improve the energy performance of new homes and some building work. They apply to new dwellings and relevant construction projects rather than all existing homes.

The revised rules come into force in Wales on 4 March 2027. In England, they will apply from 24 March 2027 for most building work, with higher-risk building work following on 24 September 2027. Higher-risk projects in England will also require approval through the Building Safety Regulator process before work can proceed.

The standards place greater emphasis on demonstrating that ventilation systems have been properly designed, installed, tested and commissioned. They also strengthen expectations around the competence of those carrying out ventilation work, alongside requirements for commissioning records and information to be provided during handover.

The guidance includes more detailed rules on ductwork. For some continuous mechanical ventilation systems, rigid or smooth semi-rigid ducts are expected to be used, while flexible ducting is limited to short final connections. Longer duct runs may require supporting calculations and drawings for Building Control.

Testing requirements are also being updated. Airflow measurements for most systems are expected to be carried out using powered anemometers, with commissioning results for new properties submitted to Building Control within five days of the final test.
The standards also tighten energy efficiency requirements for ventilation equipment by lowering permitted Specific Fan Power limits for several types of mechanical ventilation systems.

Ventilation manufacturer EnviroVent says the changes mean ventilation should be considered earlier in the design process rather than treated as a final-stage installation.

Ruth MacEachern, the company’s product manager and policy adviser, says:

“A lot of the focus around the Future Homes and Buildings Standards has understandably been on heat pumps, solar and the move away from gas boilers in new homes. But ventilation is also going through a major shift.

“The regulations are not just changing what systems need to achieve on paper. They are changing how ventilation is designed, evidenced, installed and handed over. That is why competence, early planning and proper documentation will matter more than ever.”