Changes to Approved Document F from 15th June 2022

Why is Part F changing?

Over recent decades our existing homes have been retrofitted with high performance windows, cavity wall, solid wall and loft insulation, often without regard for adequate extraction, air circulation or ventilation.

The stale air and unwanted moisture produced in homes is causing dampness, mould, and subsequent health conditions. The Regulations have been updated to promote the installation of appropriate measures.

Who is responsible for ensuring that new installations meet Part F requirements?

It is the responsibility of the Window Installer to ensure the installation meets the new requirements.

Timeless uPVC flush sash windows

Part F Regulations for Refurbishment of Existing Properties

Existing dwellings undergoing refurbishment with replacement windows will require background (trickle) ventilation. Night vents do not count and can not be used as a method of background ventilation.

If the existing windows have vents, the vents on the new windows must not be smaller than the vents in the original window.

If no vents are on the existing windows, then the replacement windows must have vents which meet Part F requirements

New Part F Trickle Ventilation Lookup Table

Habitable NON Habitable Other
Kitchen, Bedroom, Lounge, Reception, Study, Ofice, Dining, Gym, Family, Play, Loft, Library, Music Hall, Landing, Cupboard, Garage, Entrance, Conservatory Bathroom, Shower (both with or without toilet) WC, Utility, Laundry
8000mm EA No Vents Required 4000mm EA No Min - Fit largest possible
New build construction site

Part F Regulations for New Build Properties

Unless a property has been designed to use Mechanical Ventilation and Heat Recovery, then Background Ventilators will be required.

Please see the table below.

Seek expert advice if:

  • The dwelling has only one exposed façade.
  • The dwelling has at least 70% of its openings on the same façade.
  • If a kitchen has no windows or external facades for vents.

Where a kitchen and living room are not separate rooms (i.e. open plan), at least 3 vents of the same EA as for other habitable rooms should be used.

The total number of ventilators installed in a dwelling’s habitable rooms and kitchens should be no fewer than five, except in one-bedroom properties, where there should be no fewer than four.

Part F New Build Trickle Ventilation Look up Table

Minimum equivalent area of background ventilators for natural ventilation.

Room Minimum equivelant area of background ventilators for dwellings with multiple floors Minimum equivelant area of background ventilators for single-story dwellings
Habitable Rooms 8000mm 10,000mm
Kitchen 8000mm 10,000mm
Utility Room No minimum No minimum
Bathroom 4000mm 4000mm
Sanitary Accommodation No minimum No minimum

Glazpart Trickle Vent Details & Options

  • High airflow when open and very low air leakage when fully closed.
  • Supplied in component form (hoods and ventilators) and fitted to the frames with the snap on method with an option to screw on during installation.
  • uPVC colours: White, Anthracite, 2 x Cream, Agate Grey, Pebble Grey, Brown, 2 x Caramel, Black, Chartwell Green, Basalt Grey, Slate Grey.
  • Foiled / Etch finishes: Rosewood, Irish Oak, Golden Oak, Antique, White.
  • Matt painted to match aluminium powder coating.

New Glazpart Trickle Vent Performance

Glazpart Link Vent Width Through the Sash (10mm Rout) Frame / Extension (13mm Rout) Helpful Hints
Small (2,500 EA) 235mm 2,000 EA* 2,500 EA* Ideal for small WC windows or where design suits vents through sashes
Medium (4,000 EA) 380mm 3,200 EA* 4,000 EA* 75% of the windows would accommodate this vent through the frame or extension
Large (5,000 EA) 455mm 4,000 EA* 5,000 EA* Single story dwellings and useful for through the sash in a single opener

Other Important Information

  • The Big Trade Counter will only supply vents when specified on order forms or online orders.
  • The onus is on the Window Installer to ensure that new Part F requirements so please read the more detailed advice from CERTASS, ASSURE or FENSA carefully as well as Document F. Please find a link to the CERTASS guidance here and here.
  • Self-Certification bodies have changed their inspection criteria and installations will need to satisfy the requirements of Document F.
  • Please do not rely on any disclaimers that are being circulated as these will not be considered during inspections and homeowners will need to prove that they have complied with Building Regulations when selling their home.
  • If a homeowner is intent on retrofitting other ventilation measures to avoid trickle vents, this needs to be in writing as part of your contract with them.

Frequently Asked Questions

1) Does document F apply to all buildings?

Document F Volume 1 applies to ‘dwellings’. A dwelling is described as a self contained unit.

All the information on this page relates to Document F Volume 1 so only relates to self contained homes.

2) What about blocks of flats with shared communal rooms or rooms for residential purposes?

For halls of residence, hotels, residential homes, hostels etc please refer to Approved Document F Volume 2: Buildings other than dwellings.

3) Does Document F apply to New Build homes?

Document F does not apply to work subject to a building notice, full plans application or initial notice submitted before 15th June 2022, provided that work for each building is started before 15th June 2023.

However, this requires a full property assessment of any energy efficiency measures fitted since the property was built.

If 2 or more energy efficiency measures have been undertaken it is likely that the property will be less well ventilated so therefore trickle vents will be required to ensure that there is adequate ventilation.

See table 3.1 of Part F for a list of energy efficiency measures.

If it is only windows and doors that are being replaced and no other energy efficiency measures are being fitted, follow the rules for replacement windows.

4) Are there other methods of ventilation other than trickle vents?

Yes. Mechanical ventilation with heat recovery or continuous mechanical ventilation are other methods. This needs to be in working order.

5) What if the home owner is going to fit whole house mechanical ventilation or an alternative system at a later date?

You need to get a declaration from the homeowner that they will be doing this and this needs to be signed and dated and form part of your contract with the customer.

6) What if there is not enough space on the window to fit the required size of vent?

Fit vents that are as close as possible to the required size.

7) Do I need evidence of the pre-install situation?

It is advisable to take photos of the windows you are removing for your records as this could be evidence in an inspection.

8) Where should the vents be fitted on the window?

Vents should be 1700mm above floor level.

9) Are historic buildings exempt?

See page 1 of Document F. for a definition of buildings that may be exempt.

Refer to the local authority for guidance on listed buildings, historic buildings and buildings in conservation areas.

Please note that it states that work undertaken should comply with the ventilation standard in Part F where possible.

10) What if a homeowner refuses to allow trickle vents to be fitted?

As Part F comes under the Building Act 1984, building work must meet the requirements. It is the responsibility of the Installer to ensure this happens.

11) Can a homeowner sign a disclaimer saying they do not want trickle vents?

No. This would not be accepted during an inspection and the homeowner would not have the FENSA / CERTASS (or equivalent) documentation which will be required if they sell their home.

12) What about polluted areas?

If the existing property is on a major road or in an area where the pollution levels exceed the limits in Table 2.1 of Approved Document F (Volume 1, 2021 edition) expert advice should be sought.

13) Do I need to put vents on my order or will The Big Trade Counter add them for me?

Because of the sheer volume of orders we take we can’t go through each order and check for vents. Please add vents when requesting a quote if possible and check that they are on the order.

We will try to advise where possible to the best of our understanding of the Regulations.

14) Does Part F apply to Wales?

New Part F rules for Wales have not yet been released so the current rules apply to England only.

Please note that this information has been put together as guidance only and is not intended to fully replicate every item covered Part F. Our guide should be read in conjunction with the full Part F document on the Government website and the information and guidance produced by the self certification organisation you are a member of (CERTASS, FENSA etc.)

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