Chapter 2
The new HRB Framework: understanding what is (and isn’t) a ‘higher-risk building’
This chapter – at a glance
- The regulations that have been introduced to supplement the BSA and the Building Act.
- An explanation of the overarching framework that consists of two separate but aligned HRB regimes.
- The importance of understanding the definitions fully, as buildings caught within the definitions are included within the new HRB regimes.
- How the definition of HRB is different for each of the design and construction phase and the in-occupation phase of a building’s lifecycle.
- Clarification on how to properly measure building height and number of storeys.
- Clarification on which types of properties are excluded from the HRB definitions.
Introduction
Ever since Dame Judith Hackitt first referred to multi-occupancy higher risk residential buildings (HRRBs), the terms HRRBs and ‘higher-risk buildings’ (HRBs) have become part of the day-to-day vocabulary used in the context of the built environment.
Understanding the legal definition – or to be precise, definitions – of an HRB is key to understanding the duties that relate to these buildings. This can be easily overlooked, and it is important that HRRB/HRB stakeholders do not get caught out.
Not all of the content of this Toolkit relates to HRBs, but the HRB regimes explained below together form a core part of this publication.
The new rules relating to HRBs are set out in a number of different pieces of legislation; the content is detailed and complex.
The new framework for higher-risk buildings (HRBs)
One of the central features of the BSA is the creation of a new (and ‘more stringent’) regulatory building and fire safety framework that applies to HRBs in England. Earlier this year, we set out the nuts and bolts of the framework in our briefing note The new framework for HRBs begins to take shape.
One overarching HRB framework, two HRB regimes
The overarching framework is comprised of two interfacing and interlinking regimes which place duties on certain defined persons –
- first, during the procurement phase of an HRB (particularly, the design and construction stages of a project); and
- post completion of the construction work, the occupation phase of the completed HRB.
New regulations
On 17 August 2023, along with the long-awaited and much anticipated Response to the Consultation on implementing the New Building Control Regime for HRBs and wider Changes to the Building Regulations (Consultation Outcome), the government published a number of new regulations which will operate together to give effect to the new HRB regimes, to effect core changes to the Building Control system in England and put in place some fundamental changes to the Building Regulation: DLUHC finally publishes the new HRB Building Control Regulations and its Response to the 2022 Consultation on reforming the regime.
The meaning of an HRB
Under the BSA, an HRB has separate definitions in relation to each of the construction and occupation regimes:
- For the construction regime, the starting point for the meaning of an HRB is contained in Section 31 of the BSA, which amends the Building Act to define an HRB as a building that is at least 18 metres in height or has at least 7 storeys.
- For the occupation regime, the starting point is Section 65 of the BSA, which states that an HRB is a building that is at least 18 metres in height or has at least 7 storeys – but, importantly, it must also contain at least 2 residential units.
Of paramount importance is the fact that, since the BSA received Royal Assent last year, the SS for DLUHC has exercised its power to supplement these sections with the Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023 (the Regulations).
The Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023 supplements both definitions by further defining the meaning of ‘building’ and ‘storey’ as well as making provision for how the height of a building is to be determined. The Regulations also exclude specific types of building from the definition of an HRB.
A nuanced approach to defining an HRB
Specified buildings that are HRBs for the purposes of the construction regime
Regulation 2 of the Regulations specifies that hospitals, care homes and buildings containing at least two residential units will fall within the meaning of an HRB for the purposes of the construction regime where they are over 18 metres tall or have 7 or more storeys. This brings the definition of an HRB in line with the occupation regime (by including at least 2 residential units) and to ensure that tall buildings which are occupied by the most vulnerable are designed and constructed in accordance with the new, more stringent regulatory regime for building safety created by the BSA.
The meaning of a ‘building’
Regulation 4 clarifies the meaning of a ‘building’ for the purposes of both the construction and occupation regimes.
For the purposes of the construction regime, where construction relates to only one structure (defined as a roofed construction with walls), that structure will be considered the ‘building’. Where construction consists of multiple structures joined together, ‘building’, will refer to the whole set of structures.
A wide definition of a ‘building’ is taken for construction so that the BSR can consider entire structures, or sets of structures, while they are being built and so that the more stringent regulatory regime will apply to the whole of a relevant development.
A more restricted approach to defining an HRB in occupation
For the purposes of the occupation regime, the construction regime definitions apply but it is also possible to apply a more restricted definition of ‘building’ so that the in-occupation duties under the BSA are not imposed disproportionately across the whole of a set of structures where one or more of those structures are independent and do not meet the height requirements.
Accordingly, under the occupation regime, where a structure (whether or not it is attached to any other structure) contains one or more independent sections*, those independent sections are their own ‘building’ for the purposes of the BSA.
Example:
When a contractor is constructing a line of terrace properties which range from 5 to 20 metres high, as all the structures are joined, the full set of properties would be considered one ‘building’ and they would all fall under the HRB regime during the construction phase of works.
However, once completed, each property would be considered an independent section and, as such, individual ‘buildings’. The obligations in relation to in-occupation regime for HRBs would only then be applicable to those properties which were 18 metres or above or contained 7 or more storeys. The 5-metre-tall properties are still ‘buildings’ but would not meet the test in section 65 of the BSA to be considered an HRB.
Independent section* defined as: a section of the wider building which has its own entrance and exit accessible from anywhere within the section and 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.
Determining the height of a building
Regulations 5 and 6 of the Regulations clarify the method of determining whether a building is 18 metres high or 7 storeys tall as it is not as simple as counting the number of stacked windows or draping a tape measure from the roof.
The proper measuring technique is to measure from the ground level to the top of the floor surface (not the roof level) of the top floor of the building. Any storey of the building which is used only for the use of roof-top machinery or plant is to be ignored. Where the top storey is not directly above the lowest part of the ground adjacent to the building, the height is determined by measuring from the ground next to the lowest part of the building, vertically up to the horizontal projection from the top of the floor surface on the top relevant floor.
Example:
In the oddly shaped building below, the tallest part of the building is not directly above ground level and no single part of the building is over 18m. However, the top of the floor surface of the highest storey is 20 metres above the lowest part of the ground adjacent to the building. Therefore, the example building is an HRB.
When determining the number of storeys, any storey below ground is ignored. Similarly, any storey which is exclusively used for roof-top machinery or plant is not taken into consideration for the number of storeys. Further, the BSA ignores any storey which is an internal gallery floor with less than 50% internal floor area of the largest internal floor vertically above or below it.
Example:
In the building below, there are 9 levels that can be accessed in the building. However, two storeys are below ground level, level 6 is a gallery floor with less than 50% internal floor area of level 5 and the roof level only contains roof-top machinery. Therefore, for the purposes of the BSA, this building would not have 7 storeys and (assuming it is less than 18 metres tall) would not be an HRB.
Exemptions
Regulations 7 and 8 detail specific types of buildings that are excluded from the definition of HRB.
Hotels, secure residential institutions (such as prisons) and military premises (such as barracks accommodation used by the military or MoD staff) are not to be considered HRBs in relation to either the construction or occupation regimes, regardless of height or number of storeys. In addition, hospitals and care homes are excluded only from the in-occupation regime.
The exclusions are made as hospitals, hotels, care homes and secure residential institutions will already be subject to in-occupation scrutiny as a result of the RRFO which places duties on responsible persons to ensure workplaces are kept safe.
Why is this of importance?
As approximately 13,000 existing buildings will be subject to the new, more stringent regulatory requirements, and around 500 new relevant buildings are constructed every year, it is important for APs and PAPs (as defined in the BSA – see our briefing The new framework for HRBs begins to take shape) to fully appreciate the precise scope and extent of legal definitions, as well as those involved in the procurement of tall buildings and also the refurbishment of medium rise and tall buildings.
Misunderstanding the new regimes or new definitions could result in additional work being taken on when it is not required, wasting resources that could be better utilised or in a failure to comply with the BSA’s obligations – which could give rise to a conviction or a fine.
To highlight the importance of the differences, early this summer DLUHC published helpful Guidance (Criteria for being a higher-risk building during the occupation phase of the new higher-risk regime), which for some readers may have flown under the radar.
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Copyright in this publication belongs to Devonshires Solicitors LLP. The content of this publication is current as at the time of publication. It is intended as guide to the subject matter and not as legal advice, and it should not be construed as the giving of legal advice. For further information, please email one of the contacts named at the end of this publication.