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:
- Approved Document L, volume 1: dwellings
- Approved Document L, volume 2: buildings other than dwellings
- Approved Document F, volume 1: dwellings
- Approved Document F, volume 2: buildings other than dwellings
- Approved Document O covering overheating (New)
The VORTICE air solutions brochure can be found here Air Solutions Brochure