Gateway 2 for work to existing buildings

The biggest and hardest group

Work to existing higher-risk buildings is now most of what the BSR sees. In June to August 2026 it received 457 applications for internal works to existing buildings (plus 30 NHS applications), against 63 for new buildings. In the same period 141 internal-works applications were invalid or withdrawn, against 143 that reached a decision. Those aren't the same applications, but the scale of the problem is clear. The median approval time in the period was 32 weeks, pushed up by older 2025 cases still being closed. For applications submitted in 2026 it was 16 weeks (BSR data, GOV.UK).

Does your work need approval?

Building work to an existing higher-risk building needs the BSR's approval before it starts (regulation 11 of SI 2023/909). Regulation 12 sets out the application. It does not apply where the work consists only of:

• work done under a competent person scheme,
• exempt work, or
• emergency repairs covered by regulation 10.

Category A or category B?

The documents you need depend on the category. Category A is work that does any of the following (regulation 12(6)):

1. changes the building's external height or width;
2. changes the number of storeys, including adding or removing a mezzanine or gallery;
3. changes the number of flats or residential rooms;
4. changes the number or width of staircases or other escape routes;
5. involves work to the external wall, other than the work and materials excluded by regulation 7(3) of the Building Regulations 2010;
6. changes the internal layout;
7. affects the passive fire safety measures;
8. affects the active fire safety measures;
9. affects the common parts, including the external wall, where not already covered above.

Category B is any other work. Because "changes the internal layout" and "affects the fire safety measures" are broad, much routine refurbishment falls into category A.

What the application must contain

Both categories

• An application in writing, signed by the applicant.
• Contact details for the client, the principal contractor and the principal designer (or the sole contractor and the sole or lead designer).
• A statement that the application is made under regulation 12.
• A description of the existing building: current use (including each storey), height, number of storeys, and numbers of flats, residential rooms and commercial units. For category B work only inside a single flat, this description isn't needed.
• A description of the proposed work, including any change to use, height, storeys, flats or residential rooms, plus drainage, precautions over drains, steps to comply with local enactments, and when work is to be treated as started.
• A site plan at a scale of at least 1:1250, and the plans needed to show compliance with the building regulations.
• If someone applies on the client's behalf, a signed statement from the client confirming they agree and that the information is accurate.

Category A adds

• a competence declaration;
• a construction control plan;
• a change control plan;
• a mandatory occurrence reporting plan;
• a building regulations compliance statement;
• a fire and emergency file;
• a partial completion strategy, if any part will be occupied before the work is complete;
• building safety levy information (regulation 17A, from 1 October 2026), where the work provides dwellings or purpose-built student bedspaces: the planning status, whether it is major residential development, the local authority, and the number of dwellings or bedspaces. Regulation 12(3) doesn't ask category B applications for it.

Category B adds

"Fire safety compliance information" where Part B (fire safety) of the Building Regulations applies: the fire safety design principles, concepts and standards used, with plans showing how the work complies. The other category A documents are optional, but the BSR can require any of them by written notice before it decides.

Why these applications fail

In the BSR's review of a selection of rejected applications for existing buildings ("Getting building control applications right"):

• 89% did not contain sufficient detail;
• 80% did not meet the legal requirements for approval of work to an existing higher-risk building;
• 50% described work that would contravene building regulations;
• 43% described only a small part of the work actually planned.

That last point is specific to existing buildings. Describe all the work, including enabling works and anything that touches fire doors, compartmentation, services penetrations or the common parts. Also describe the building as it is now, not as originally designed. See why Gateway 2 applications fail for the full findings.

The rules may change

The BSR received far more category A applications than expected, and in 2026 the government consulted on narrowing category A. Its response (9 July 2026) says it is "minded to proceed" with moving most work inside individual flats to category B, with exceptions such as work affecting active fire safety, load-bearing walls, external walls (excluding windows) and fire doors to communal areas. It is still exploring a second option for small-scale communal work. Nothing has changed yet: any change needs a new statutory instrument, and no date has been set (GOV.UK consultation and response). Until then, regulation 12(6) applies as written.

Check your pack

The free Gateproof checker handles applications under regulation 12. Tick Work to an existing HRB, and Category B work if that applies, under Application type. It then looks for the documents and information that apply to your category, flags statements of intent, and cross-checks facts between documents and drawings. It doesn't yet handle the single-flat exception: for category B work only inside one flat, ignore "not found" results for the description of the existing building. It can't decide your category for you, or judge whether the detail is sufficient.

Sources

• The Building (Higher-Risk Buildings Procedures) (England) Regulations 2023, SI 2023/909, regulations 10, 11 and 12 (legislation.gov.uk, version from 1 October 2026).
• BSR, "Building Safety Regulator building control approval application data June to August 2026", GOV.UK, data as of 31 August 2026.
• BSR, "Getting building control applications right", Making Buildings Safer.
• MHCLG, "Improving proportionality and building safety outcomes in building control: categorisation of higher-risk building work", consultation (26 March to 28 May 2026) and government response (9 July 2026), GOV.UK.

Written on 13 October 2026 and paraphrased from the sources above. Check the current regulations and guidance before relying on it. This is general information, not legal or compliance advice. Contains public sector information licensed under the Open Government Licence v3.0.