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

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.