What do the new Building Regulations changes mean for ventilation?

Let us simplify it for you!

The new Building Regulations comprises of five new Approved Documents, including changes to Part F (ventilation) which will come into effect from 15th June 2022.
The significant update provides an uplift to existing energy efficiency standards for homes and marks a stepping stone towards the introduction of the Future Homes Standard in 2025.

So what are the main changes?

The system names have changed

 Systems 1, 3 and 4 have been removed. The systems are now known as:

  • Natural ventilation with background ventilators and intermittent extract fans (formerly system 1)
  • Continuous mechanical extract ventilation (formerly system 3)
  • Mechanical ventilation with heat recovery (formerly system 4)

There has been structure changes to the documents

  • There is a new regulation – Approved Document O – Overheating
  • ADF has now been split into volume 1 – Dwellings and Volume 2 – Buildings other than Dwellings
  • All compliance guides are now obsolete and incorporated into the approved documents
  • A Home User Guide for new dwellings should be provided

Background ventilation has changed

  • Background ventilation is now worked out as equivalent area (mm2)
  • Continuous Mechanical Extract trickle vents should now provide 4000mm2 EA in each habitable room (previously 2500mm2 FA)
  • For existing homes all replacement windows should be fitted with trickle vents

Design air permeability has changed

The guidance has split homes into two categories – Less Airtight Dwellings and Highly Airtight dwellings. Highly airtight dwellings have to achieve one of the following:

a. A design air permeability lower than 5m3/(h/m2) at 50Pa.

b. An as-built air permeability lower than 3m3/(h/m2) at 50Pa

Rates have increased for bedrooms

  • The ventilation rate for the bedrooms has now increased
  • Additions for additional occupants on ADF2010/13 has been removed
  • Still take the higher of the two calculations as the whole dwelling ventilation (trickle) rat


The new Building Regulations approved documents can be found here:

Should you require any further information on these changes one of our technical team would be happy to assist and offer guidance and advice. Simply email sales@vortice.ltd.uk or call on 01283 492949 today!

The VORTICE air solutions brochure can be found here Air Solutions Brochure 

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