Understanding 'Independent Sections' in the Context of High-Risk Buildings (HRBs) Under the New Building Regulations

Fri 05/16/2025 - 14:45

Introduction

The introduction of the new building safety regime in the UK has brought significant changes to how developments are assessed, approved, and regulated—particularly in the context of Higher-Risk Buildings (HRBs). A crucial but often misunderstood concept within this framework is the role of independent sections in determining whether a development falls within the HRB regime or not and, therefore, whether it must go through the Building Safety Regulator (BSR) or more Traditional Building Control Body (BCB).

What Is a Higher-Risk Building (HRB)?

Under the Building Safety Act 2022 and the associated secondary legislation, an HRB is typically defined as a building that is at least 18 metres in height or has at least 7 storeys, and contains at least two residential units. This definition triggers specific requirements, such as applications through the BSR at Gateway 2 (building control approval) and Gateway 3 (completion/final certification).

The Role of Independent Sections

A key nuance in determining whether a project qualifies as an HRB is whether the building consists of independent sections. This distinction becomes especially relevant in mixed-use developments, phased developments, or buildings that contain a mix of residential and non-residential spaces.

An independent section refers to a part of a building that follows the key requirements within The Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023. This includes operating and being accessed separately to the HRB.

The presence of independent sections allows for a more granular assessment. For example:

A multi-use building with a commercial and residential spaces accessed via separate entrances but sharing emergency and maintenance routes only.
A building with multiple towers or blocks joined at a podium might be assessed as separate independent sections if each block meets the criteria independently.

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Why it matters?

If a particular section of a development can be deemed independent and does not meet the HRB threshold on its own, it may fall outside the scope of the HRB regime. This has several implications:

Regulatory Pathways

HRB: Must be submitted to the BSR for Gateway 2 and Gateway 3 approval, with oversight by a Multi-Disciplinary Team (MDT).

Non-HRB: Can proceed through traditional building control routes via Local Authorities or Registered Building Control Approvers (RBCAs).

Programme and Costs

Engaging with the BSR can introduce additional review periods and procedural requirements, potentially impacting project timelines.

Identifying and justifying non-HRB sections early in the design process may streamline approvals and reduce administrative burden.

Documentation and Evidence

It is essential to provide clear justification, supported by architectural and fire strategy documents, for treating parts of a development as independent.

This includes demonstrating that the section is structurally, mechanically, and operationally self-contained.

Increased Commercial Value

Reduced regulatory delay

Fewer legal liabilities

Faster Transaction times

Regulatory speed for minor changes.

Increased Marketability

Project and Development Planning – Value can be added to any project with reduced lead times for development and procurement.

Designating an commercial space within a HRB can increase demand and can lead to higher rental yields and faster occupancy.

Conclusion

The concept of independent sections is not just a technicality—it is a pivotal factor in navigating the new regulatory landscape under the Building Safety Act. A strategic and well-evidenced approach to identifying HRBs and non-HRBs within a development can offer real efficiencies while maintaining compliance and safety.

If you're planning a complex or phased project, or if you're unsure how your development aligns with the HRB definitions, engaging early with our SOCOTEC Building Risk and Compliance team is essential

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