Building Regulation Changes – The perceived impact!


Written by Tom Kimber

Tom is an Associate Architectural Technician with BoonBrown offering expertise within the company on building regulations and technical standards.

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You will be aware there are significant updates to Parts L (Thermal) and F (Ventilation), and two new documents, Parts O (Overheating) & S (Electric vehicle charging) of the building regulations that are coming into force on the 15 June 2022.

These are the most significant changes to the regulations in recent years.

Without going into the technical details of each change, Parts L & F have been revised and Part O introduced as an interim step to assist the Governments desire to get to Net Carbon Zero. Part S sets out parameters for electric vehicle charging.

For past changes to the regulations, there was an obligation to secure the building regulations application through the interim period by making a start on site.  Now however this has been increased to a ‘significant start’ on site.  Where previously the start on site could have been a very light touch, now the significant start is requiring that all the footings for the development are to be poured, or the site drainage for the scheme is to be installed.

We have been seeking clarity from local authority building control, private assessors and the NHBC and the uniform response is that if you have a site of 1 or 100 units, the footings or drainage of all the site will need to be installed by 15 June 2023 if you have a building regulation application running before this year’s deadline.

This would include all phases of a large, phased site, where previously if regulations changed then the plots not yet started would still be built under the older regulation set.

As a practice we are experiencing a desire from clients to submit building regulation applications prior to 15 June 2022 to ensure that the current regulations can be built to, giving the year’s grace to get the footings for the site poured.

The new regulation changes will now introduce a higher level of thermal performance and airtightness to the building fabric, improving the ventilation strategy and assessing and limiting the overheating (solar gains) within a building.

For example, in Approved Document L domestic external wall U values have been tightened to 0.18 W/m2/K, ground floors to 1.3 W/m2/K and roofs to 1.1 W/m2/K.

Within Approved Document F the air permeability for new build residential has been reduced to 5 from 10m3/m2h. Whole building ventilation rates have also increased.

These changes will not be overly difficult to achieve in themselves. As a practice we have been working with very similar U values over recent years on a wide range of projects where planning permissions have already required a betterment of the existing regulations, and in our experience with air tightness, with good site control most of our projects have achieved below 5m3/m2h in their air tests.

Approved document ‘O’ is principally directed at new build residential units, although does include live/work premises and is the driver for looking at the solar gains and improving the removing the excess heat within the home.

The known impact of this is that the likely input of a thermal modelling specialist at a far earlier point of the project. Currently, it is likely that the earliest point that many consultants are employed is once planning has been approved and a project is moving into the working drawing package stage.

The implications of the new regulations will require design teams to seek guidance from thermal modelling at a far earlier project stage.

If this isn’t actioned, then there is a risk that once planning is permitted and the next stage of the design development progresses, there will undoubtedly be the requirement to go back to planning to adjust the designs, adding in time and cost to the client.

Approved document S seems to regularise the addition of electric vehicle charging points on sites. It is the first approved document to my knowledge to introduce a financial cap as a defined figure. This does not appear to be related to an index linked increase, so time will tell how this document will be affected by the cost-of-living increases that the country is currently experiencing.

It is understood that although we are very close to the new regulations being adopted, the final SAP software is yet to be officially distributed to the SAP consultants. Many will have had a chance to see the ‘Beta’ testing version, but the final issue is still to be released.

As a practice with an office in Somerset, we wonder if there will be a delayed impact on planning due to these regulation changes principally due to the current phosphate and nitrate issue affecting the Somerset levels and their catchment area.

What about schemes already submitted for a planning permission?

For the last couple of years many planning applications in Somerset have been in stasis until the phosphate and nitrate stalemate has been concluded.

These will all have been designed based on the principles of the current building regulations, and the perception is that once the planning is released, many sites will need to be appraised against the new building regulations with the probability that planning will need to be resubmitted.

For any projects going through the planning process, it could be recommended to submit your Building Regulations application before the 15 June 2022, as this can be done with just the planning application reference number and a limited set of drawings (site plan, building plans and elevations).

This would provide the year’s grace on having to adopt the new changes, however in Somerset would still be dependant on the Phosphate issue being concluded and the planning permission being granted.

With significant updates like this there will be a period of settling into and understanding the changes and their impact.

No doubt, the next 12 to 18 months will be an interesting time whilst consultants, manufacturers and clients all start to piece together the changes required.