The building control regime for higher-risk buildings and its impact on mixed-use buildings

Introduction

Much of the focus of the impact of the Building Safety Act 2022 and the new building control regime is on residential properties; however, it also has a significant impact on commercial premises where these are deemed part of a higher-risk building. Subject to limited exclusions, a higher-risk building is a building in England which is at least 18 metres or seven storeys high and which contains at least two residential units (“HRB”) .

The new regime involves increased regulation from the Building Safety Regulator (the “BSR”) (including three gateway approvals), which apply to:

• the construction of a new HRB;
• building work to an existing building that either makes it an HRB, or stops it being an HRB; and
• building work to an existing HRB (unless it consists of exempt or excluded works)

The gateway approvals require the compilation of detailed information for submission to the BSR in order for HRBs to pass three checkpoints at key stages in construction and design: Gateway 1 at the planning stage, Gateway 2 before construction begins, and Gateway 3 upon completion.  Gateways 2 and 3 are hard stop decision points that require BSR approval to ensure building safety requirements have been met before the project can progress to the next stage.

However, the rollout of the new regime has not been seamless, and there have been significant delays to approval by the BSR caused by a number of factors including inevitable teething issues, lack of resource and knowledge sharing within the building safety community.

What does this mean for owner/operators of mixed use buildings?

We are seeing these delays significantly impact clients who are owners or operators of mixed-use HRBs and are seeking to carry out works (even of a minor nature) to refurbish or upgrade their commercial premises. 

For these clients, it may be possible to split the overall structure (where the structures are connected) into ‘independent sections’, which will be considered as separate ‘buildings’.  If those ‘buildings’ do not meet the requirements of an HRB then they will not have to undergo the same regulatory requirements as an HRB (i.e. they do not have to participate in the Gateway approvals etc). 

It is therefore important that owner/operators understand the definition of an ‘independent section’ and how it can be applied to their buildings. It is also key that, where local authorities refuse to consider applications for building control approvals (on the basis that all or part of the work to which the application or notice relates is higher-risk building work for approval by the BSR ), owner/operators understand the options available to them.

As we are seeing an increasing number of disputes in this area, we have summarised below the law relating to independent sections and the steps required to challenge local authority’s decisions to help mitigate the potential legal and commercial risks associated with an incorrect classification of proposed works.

Are my commercial premises an independent section?

The definition of an HRB is supplemented by The Higher-Risk Buildings (Description and Supplementary Provisions) Regulations 2023 (the “2023 Regulations”), which contain certain exemptions and also provides the mechanism by which a building can contain an ‘independent section,’ which will be deemed a separate ‘building’.  As noted above, if the building is not an HRB, this gives owners and operators the ability to exclude certain sections of their premises from the gateway regime.

Broadly speaking, an independent section is any section which has an independent access and is not linked to a residential unit; however, the regulations and definitions are not without their complexities.

In short, Regulation 4 (6) of the 2023 Regulations defining an independent section as a building that has:

1. access, which can be reached from anywhere in the section, for persons to enter and exit the wider building; and
2. either:

• has no access to any other section of the wider building; or
• only has access to another section of the wider building which does not contain a residential unit.

Regulation 4(7) of the 2023 Regulations provides that “access” means a doorway, archway or similar opening but does not include a doorway, archway or similar opening intended for exceptional use including emergency use or use for the purpose of maintenance.

This definition causes potential uncertainty; for example, in respect of HRBs where the primary means of access are lifts, which is not included in the definition of ‘access’. Ultimately a surveyor must determine what constitutes an independent section, based on their inspection of the site and these legal guidelines.

The regime in practice

It is therefore possible in principle to: carve out an independent section from an HRB to avoid the regulatory regime under the BSR (provided that the independent section does not constitute a HRB in its own right).

In these circumstances those works to an independent section ought to be assessed through the local authority building control route and not the BSR on the basis that none of the notified works constitute higher-risk building works.

However, in our experience the complexities associated with this analysis might result in local authorities incorrectly applying the higher-risk building ‘test’ in isolation to the structure as a whole (i.e. foregoing the application of the independent section criteria first) out of an abundance of caution, such that they refuse to consider applications for all works and route them through the BSR.

In those circumstances, owners/operators have two options:

1. accept the local authority’s decision and engage with the BSR; or
2. challenge the decision of the local authority via a Scope Determination Appeal.

In order to try and pre-empt any issues, we also believe the building owner/landlord has a vested interest in taking a more proactive role in any tenant application to the local authority, potentially including a detailed explanation of the 2023 Regulations and why it is felt the conditions for an independent section have been met.

Scope Determination Appeals

Where a local authority refuses to consider an application for building control approval on the ground that all or part of the work to which the application relates is higher-risk building work  (i.e. concerns work to a higher-risk building), the person intending to carry out the work may appeal to the Ministry of Housing, Communities and Local Government (“MHCLG”) on the ground that none of the work is higher-risk building work.

The ground for appeal is narrow and requires a clear, precise analysis on the part of the appellant as to how the various criteria operate such that the higher-risk building regime does not apply to the notified works.

Furthermore, the appeal process operates on tight deadlines (the appeal must be made within 28 days of the local authority’s refusal to consider the application) and the notification and other procedural requirements (which are stringent) must be adhered to, failing which the appeal will not get off the ground.

With that in mind, owners/operators need to be prepared for the prospect of commencing a Scope Determination Appeal at the point of making an application to the local authority.

Conclusion

In summary:

• The application of the 2023 Regulations insofar as they relate to independent sections and higher-risk building works is complex and requires careful appraisal on a case-by-case basis prior to submitting any application to the relevant local authority.
• Local authorities face a significant challenge in applying these principles and early proactive engagement is advisable to work through issues collaboratively and minimise the risk of incorrectly refused applications.
• Should an application for an independent section be refused incorrectly on the ground that the work is higher-risk building work, recourse is available by appeal to the Secretary of State for MHCLG in accordance with Section 101A of the Building Act 1984.
• Being prepared can make a significant difference to mitigating the risk of rejected or delayed applications to the local authority, as well as navigating a Scope Determination Appeal should that route become necessary.

Our team has extensive experience of assisting clients navigate these issues, including obtaining successful results in Scope Determination Appeals to the Secretary of State for MHCLG, and can work with you to provide solutions. 

This article was first published in Building Magazine in March 2026