Check new ventilation rates

The new regulations update the minimum dwelling ventilation and background ventilation rates. 

These can be found in the updated Part F building regulations.

Combine passive and mechanical ventilation

You must show local building control how you’ve:

• used the most beneficial energy and carbon efficient ventilation strategy for your design and location
• achieved adequate ventilation levels and rates in line with minimum requirements

You must inspect, test and commission mechanical ventilation systems in line with the new regulations and do the following for local building control:

• test the air flow rate of all fans to the appropriate standards using approved methods and equipment
• record measured flow rates 
• keep all installation and commissioning certificates

You must also make sure mechanical systems meet the new conservation of fuel and power requirements under the updated Part L building regulations.

Adapt your design process

You must adapt your design thinking to consider:

• the ventilation implications of more airtight dwellings
• minimising noise from mechanical systems - including both continuous and intermittent mechanical ventilation
• local conditions - including noisy streets and minimising the ingress of external pollutants
• ease of access for maintenance and checks
• the air flow resistance of all components

The new regulations also introduce conditions around the use of flexible ductwork. Rigid ductwork remains the preferred solution.

Record your design decisions

You must document your decision-making throughout your design process.

Use this documentation to show SAP assessors and local building control your decisions and how your designs meet the new regulations.

Find out how to provide information for SAP assessors and building control.


Provide information for homeowners

You must also provide details for homeowners about how ventilation systems are controlled and maintained within their new homes.

Find out how to provide homeowners with information about their new homes.

Keep up to date

Use the Future Homes Hub to keep up to date with changes to the building regulations and the introduction of the Future Homes Standard.

Check what you need to do to meet the new regulations through our detailed guides.

Find out more

Find other new regulations in the official Approved Documents on GOV.UK:

• Conservation of fuel and power: Approved Document L - ‘Part L’
• Overheating: Approved Document O - ‘Part O’
• Ventilation: Approved Document F - ‘Part F’