Higher-risk building

The Building Safety Act 2022, defines “higher-risk building”as:

(a) is at least 18 metres in height or has at least 7 storeys, and
(b) contains at least 2 residential units.

In the context of the UK Building Safety Act (BSA), "higher-risk buildings" (HRB) refer to buildings that pose greater potential risks to the safety of occupants and the public due to various factors, such as height, occupancy, use, and construction materials. The BSA introduces a regulatory framework aimed at improving the safety and standards of higher-risk buildings, with a focus on addressing fire and structural safety risks.

Higher-risk buildings typically include residential buildings of a certain height or with specific characteristics that increase the likelihood or severity of fire incidents or structural failures.

Care homes and hospitals are included. Various properties are excluded including (but not limited to) those consisting entirely of a secure residential institution, hotel or military barracks. The Secretary of State has the power to flex the regime to apply to new circumstances (including new building safety risks) in the future.

The purpose of the Higher-Risk Buildings (Descriptions and Supplementary Provisions) Regulations 2023 is to specify descriptions of buildings to be included in the definition of “higher risk building” in the Building Act 1984 and to supplement that definition, as well as the definition of “higher-risk building” in the Building Safety Act 2022. Buildings defined as higher-risk buildings are included within the scope of the new more stringent regulatory regime for building safety, created by the 2022 Act.

In the Grenfell phase 2 final report recommendations for the construction industry, which was the final element of the Grenfell inquiry, held some criticism of the definition of “higher-risk building” used as in the Building Safety Act, for being primarily based on height only. A building at least 18 metres in height (or has at least seven storeys) and contains at least two residential units is deemed as higher.risk. The report stated however, that, 'defining a building as “higher- risk” by reference only to its height is unsatisfactory and arbitrary in nature. More relevant is the nature of use, in particular, the presence of vulnerable people, for whom evacuation in an emergency presents difficulty. It is therefore recommend that the definition of a higher-risk building for the purposes of the Building Safety Act be reviewed urgently'. (113.7)

NB BSI Flex 8670 V3.0, Built environment – Core criteria for building safety in competence frameworks – Code of practice, April 2021 Version 3, published by The British Standards Institution in 2021, defines a higher-risk building (HRB) as a: ‘building subject to enhanced regulatory requirements or where risks might be considered elevated. NOTE For example, as a result of the physical characteristics of the building, the way in which the building is used or as a result of human factors.’

However, Grenfell Tower Inquiry: Phase 2 report overview, report of the public inquiry into the fire at Grenfell Tower on 14 June 2017, published in September 2024, states: ‘For the purpose of this and our other recommendations we have used the expression “higher-risk building” in the sense in which it is used in the Building Safety Act, that is, a building that is at least 18 metres in height (or has at least seven storeys) and contains at least two residential units. However, we do not think that to define a building as “higher-risk” by reference only to its height is satisfactory, being essentially arbitrary in nature. More relevant is the nature of its use and, in particular, the likely presence of vulnerable people, for whom evacuation in the event of a fire or other emergency would be likely to present difficulty. We therefore recommend that the definition of a higher-risk building for the purposes of the Building Safety Act be reviewed urgently.’