Government introduces three-pronged commencement definition

Buildings will be split into three categories, each with separate rules on when building work is deemed to have started, under an amendment to regulations.

Last week, the government laid a raft of amendments to Building Regulations following a year-long consultation after the introduction of the Building Safety Act 2022.

One change – which will apply to all buildings – covers the definition of when work starts on site, to ensure that more work has been completed than under present guidance on when work is defined as having started.

However, the proposed single definition of “commencement”, included in the original consultation, has been scrapped in response to concerns from the sector.

The government said: “We have amended the proposed definitions of commencement.

“The new definition we have developed for existing buildings is specific to different types of building work, addressing the concerns around the complexity of the definition proposed in the consultation.”

In the original consultation, the government proposed a single definition for commencement, but a number of respondents raised concerns that it was set too far into the building process for complex sites.

The definition was to include the completion of the substructure of a building up to and including the foundations and any basement level, the construction of walls up to damp-proof course level, the laying of foul- and surface-water drainage, and ground-floor works.

A number of respondents warned that, on complex projects, such works could take more than three years from building-control approval – the timescale after which the approval would lapse.

In response, the government said it would create three new definitions of commencement for different types of building work:

• For complex buildings: when the foundations supporting the building and the structure of the lowest floor level of that building (but not the other buildings or structures to be supported by those foundations) are complete.
• For non-complex buildings or a horizontal extension of a building: when the subsurface structure of the building or the extension, including all foundations, any basement level and the structure of ground-floor level, is complete.
• Any other building work: when 15 per cent of the proposed work is complete.

The government said that it “believes these amended definitions will support the policy intention: preventing those that do not have the intention to commit to the building work at the time the plan was deposited to no longer be able to build out to old standards through a weak definition of commencement”.

It said that the move to tighten the definition of commencement outlined in guidance was undertaken because “some developers interpret it to mean digging a hole on site”.

“This approach allows developers to undertake notional building work quickly but then not build out the site until years later,” it said.

Angus Dawson, partner at law firm Macfarlanes, said: "It will be interesting to understand how the government distinguishes each category. There will inevitably be grey areas between each."

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