Up to 5% discount on all products. Extra: Free upgrade of Insulation to All cladding orders.

How will the new building regulations affect the fenestration sector?

Much to the anticipation of many within the fenestration sector, the UK Government recently released its updated building regulations. While maybe not the most interesting thing for the country as a whole, it is a hot topic among industry professionals for its impact on current and future projects.

This new update consisted of several noteworthy revisions. Through the following, we’ll review what the most pertinent of these changes are, and what they mean for your work.


A change many were expecting to see come out of these updates, minimum u-values for windows have been adjusted within the guidelines. This can be found in Part L of the document, which revise the prior u-value minimum of 1.6 to 1.4 for new windows in existing dwellings. There has also been a shift for doors, with values being dropped to 1.4 from 1.6. Under these new values, it’s generally conceivable for any standard double glazed window with the right specifications to meet the updated guidelines, thus removing any straightforward requirement for triple glazing.

The terms of the regulations go into detail about how these new rules may apply in different cases, which you can read in further detail on page 25 here: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1040935/ADL1.pdf 


Another notable change within these documents can be found in Part F and pertains to ventilation. This is one of the more major updates to the regulations, with a new requirement for all windows going into new or existing dwellings to have trickle ventilation.

The new guidance goes into detail on background ventilation, with this specific change communicated in the following excerpt.

Background ventilators

1.52 All rooms with external walls should have background ventilators. If a habitable room has no external walls, paragraphs 1.42 to 1.44 should be followed.

NOTE: A window with a night latch position is not adequate for background ventilation, due to the following:

  • The risk of draughts.
  • Security issues.
  • The difficulty of measuring the equivalent area.

Source: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1040932/ADF1.pdf

This is all part of the larger purge ventilation section in Part F, which begins on page 19 of the PDF linked above.

There is a gap in this specific provision, as mechanical ventilation systems or extractor fans can theoretically be fitted in each room instead of windows. That not being a realistic alternative, however, trickle vents in windows remain the most readily available option for installers in these new guidelines.


This is a somewhat overlooked update but yet will still hold value to fenestration industry professionals. Part H of the revision includes some changes to section 4.21, which in short, reevaluate standards for airtightness as it pertains to installation. This can be seen in the following excerpt, which is from page 40 of the referenced document.

Windows and doors: to ensure continuity of the air barrier, window and door units should connect to the primary air barrier and window and door frames should be taped to surrounding structural openings, using air sealing tape. Compressible seals or gun sealants may be used to supplement taping.

Source: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1040935/ADL1.pdf

While not relevant for everyone, this particular change will be important for installers who fit windows and doors into new dwellings or home extensions. It means these individuals will likely need to adapt their methods, such as through the use of expanding sealant tapes and their counterparts.

The Response

It is important to keep in mind that while this list covers some of the more industry-relevant changes to the regulations, there is still a lot more to learn from the documents. This simply serves as a brief rundown of areas of interest for those working in fenestration, however certainly isn’t exhaustive. Other topics for possible review include changes affecting porches and conservatories.

In regards to what’s been referenced here, however, a particular change has gotten many people talking, raising questions as to whether or not it will be here to stay. This is for the new requirement for all new windows in new and existing dwellings to have trickle ventilation, which has experienced quite a bit of pushback. It’s mainly a problem for installers, with many arguing that this could add time and money to what is already a complex process. Despite passionate protests, these updates appear to be on track to become the new regulations going forward, unless there are some major changes in the following months.

Questions Yet To Be Answered

There are a number of unanswered questions that these new Building Regulations raise.

What about the transition date?

Although the UK Government has designated June 15th 2022 as the official date from which these revisions will become law, it’s less than favourable to many within the fenestration industry. It’s the case for most fabricators and installers, who already have months of work pre-scheduled for this time. This means that orders sold upon or directly after the release of this revision would need to comply with their changes, such as in the inclusion of trickle vents. This leaves sector professionals in a tough spot, with many now needing to adapt their plans accordingly. Given the short time period the current start date allows for, it’s very possible we could see some developments on this in the coming weeks to months.

Who is going to enforce these updated rules?

It remains unclear as to how these changes will be effectively implemented in terms of proper adherence. With a lack of enforcement, it will be quite easy for homeowners to find professionals okay with meeting their preference against things like trickle vents, leaving those who do comply at a disadvantage in terms of business. This is something that necessitates further detail in terms of detail and strategy in order to make these updates effective.

So far, it seems that many in the industry are still trying to come to grips with the sheer number of changes set to occur come June 15th. As more information becomes available, it will be interesting to see how the market adapts – and what kind of impact these revisions will ultimately have on both homeowners and professionals.

In any case, these new revisions provide a much-needed update to the Building Regulations and those in the fenestration industry would do well to acquaint themselves with them.

Recent Posts
Share to social

Our team are
ready and waiting
to help you...

Greenoak Concept & Design have been raising the standards for more than 10 years.

More about us: We’re an independent Essex-based specialists in high quality UPVC Windows, Doors, Tiled Conservatory Roofing, Wall Cladding, and Fascias, Soffits and Guttering.


Free Quotation