For new buildings in England and Wales there are two principle pieces of legislation that address building safety: the new Building Safety Act 2022 and the established Building Regulations. The height of the proposed new building is relevant to the regimes that apply under both.

The Building Regulations

The Building Regulations apply different building safety regimes depending on the height and categorisation of a building and adopts the term 'relevant building' to identify those buildings to which the most stringent regime applies.

Under Regulation 7(4) a relevant building is defined as a building with a storey (not including roof-top plant areas or any storey consisting exclusively of plant rooms) at least 18 metres above ground level (measured from the lowest ground level adjoining the outside of a building to the top of the floor surface of the storey) and which:

  • contains one or more dwellings;
  • contains an institution; or
  • contains a room for residential purposes (excluding any room in a hostel, hotel or boarding house);

The full regimes (including those for 'relevant buildings') that apply under the Building Regulations are set out in what is known as Approved Document B the most recent version of which was published in 2019, amended in 2020 and amended again in June 2022 (although these latest amendments only take effect from 1 December 2022). Approved Document B comes in two flavours according to building usage: Dwellings; and Buildings other than Dwellings.

The most recent June 2022 (introduced by virtue of the Building etc. (Amendment) (England) Regulations 2022) will remove the exclusion for "any room in a hostel, hotel or boarding house" under paragraph (iii) above with effect from 1 December 2022 onwards for buildings where work has commenced or will commence within 6 months, thus widening the scope of the 'relevant building' regime.

A 'building' is defined in the Building Regulations as any permanent or temporary building but not any other kind of structure or erection, and a reference to a building includes a reference to part of a building. That definition therefore means that when considering how the building safety regimes are to be applied, one needs to consider a building as a whole, not just parts of it. So, if any part, or section, of a building meets the criteria to be a 'relevant building', the whole building falls under that more stringent regime.

Building Safety Act 2022

One of the key provisions of the BSA was to introduce a new organisation – the Building Safety Regulator – who will have responsibility for a new regime regulating "higher risk buildings" in England and Wales with the stated aim of ensuring proportionate steps are taken to deal with building safety risks through prevention, control, mitigation and ongoing management throughout the lifecycle of a building.

Under s65 of the BSA a “higher-risk building” means a building in England that:

(a) is at least 18 metres in height or has at least 7 storeys, and

(b) contains at least 2 residential units.

In addition, Section 31 of the BSA inserted a new Section 120D to the Building Act 1984 introducing a new definition of 'higher risk building', being a building that is at least 18 metres in height or has at least 7 storeys, and is of a description specified in regulations made by the Secretary of State.

So, though the '18m' height is the same as the definition of 'relevant building' under the Building Regulations, the criteria are not quite the same and the precise categories of buildings have not been clarified. However, Section 65 also provides that the definition may be changed by means of further regulations by the Secretary of State. Indeed, the results of the Government consultation considering the types of buildings categories that will fall within the remit of the new regulator (and the secondary legislation that will follow) can be expected soon since the Government currently plan for the Building Safety Regulator to go "live" in April 2023.

In summary, whilst height does matter when considering the applicable building safety regime to apply, it is not the only relevant characteristic – and as things stand those characteristics are not consistent across the different legislation.

Whilst the Government's previously stated intention was that hotels would be excluded, given the removal of the exclusion covering 'any room in a hostel, hotel or boarding house' from the 'relevant building' definition in the Building Regulations, it may be an indication that the BSA definition will follow suit. In any event clarity from the forthcoming regulations will no doubt be welcomed by the industry.


Andrew Groom

Senior Associate

Louise Shiels

Head of Dispute Resolution and Risk & Partner

Eric Johnstone

Legal Director