Planning Gateway One: which buildings are caught
Gateway One catches buildings with two or more dwellings or educational accommodation that reach 18 metres or seven storeys. Both limbs must be satisfied, and measurement decides marginal cases.
Planning Gateway One catches a building that satisfies two conditions at once: it contains two or more dwellings or educational accommodation, and it is 18 metres or more in height or has seven or more storeys. Meet both and the application for planning permission must be accompanied by a fire statement on the form published by the Secretary of State, and the council must consult the Health and Safety Executive before it decides.
The requirement comes from article 9A of the Town and Country Planning (Development Management Procedure) (England) Order 2015, inserted in 2021 and in force from 1 August that year. Miss it and the application is invalid, which on a tall residential scheme means losing weeks at the front of the programme rather than at the end.
The two-part definition
Both limbs have to be satisfied. A 22-storey office is not caught, because it contains no dwellings and no educational accommodation. A six-storey block of 40 flats at 17 metres is not caught either, because it fails the height and storey test.
Educational accommodation is the limb people forget. Student halls and boarding accommodation attached to a school sit alongside flats in the definition, so a purpose-built student scheme at 19 metres is squarely within Gateway One even though nobody would call the rooms dwellings.
Mixed-use buildings need care. A tower with retail at ground floor, offices to level four and residential above is a building containing two or more dwellings. The commercial content does not take it out of scope.
How height and storeys are measured
Height is taken from ground level to the floor surface of the top storey, not to the parapet or the top of the plant screen. A roof-top level containing only plant or machinery is left out of the count.
Storeys are counted excluding those below ground level, and again excluding a roof-top plant-only level. Where the ground falls across the site, the measurement convention matters a great deal, and the difference between 17.6 metres and 18.1 metres is the difference between two entirely different consenting routes.
Three practical points follow. Measure from the drawings that will be submitted, not from an early massing study. Record the assumption in writing, because it will be tested. And if the building sits within half a metre of the threshold, either design it clearly under or accept that it is in and plan accordingly, because a marginal case invites an argument with the council at validation.
What the fire statement has to be
A Fire Statement is a planning document about the fire safety implications of the development as it affects the planning decision: site layout, the position and size of the building, access for fire appliances, water supplies for firefighting, and the principles of the evacuation strategy insofar as they shape the design.
It is not a building regulations submission and it is not a full fire engineering strategy. But this is a report type where the law effectively requires competence. A fire statement should be prepared by someone with the necessary fire engineering competence, and an AI-assisted draft is a starting point for that person rather than a substitute for them. The same applies with more force to a Fire Safety Strategy prepared to BS 9991 or BS 9999.
The Health and Safety Executive publishes guidance on what it expects to see at Gateway One and how it responds. Reading it before drafting saves a round of comments.
The form itself is prescribed, so do not substitute a consultant's house template. Councils validate against the published form, and a document that answers the same questions in a different order is routinely returned.
Change of use and works to existing buildings
New build is the obvious case. The less obvious ones catch people out.
Converting an existing office block of eight storeys into flats creates a relevant building where none existed, so the application needs a fire statement. Adding two storeys to a five-storey block of flats may push it over the storey count. Material alterations to an existing relevant building can bring the requirement into play even where the height does not change.
Where a scheme is being taken forward in stages, the question is what the completed building will be, not what stands today.
Demolition and rebuild on the same footprint is a new building and is assessed as one. A scheme that reduces an existing relevant building below the threshold takes it out of scope for the works that follow, though the fire safety design questions do not disappear with the planning requirement.
The HSE consultation and what it does to the programme
Once the fire statement is validated, the council consults the Health and Safety Executive as a statutory consultee. The response feeds into the officer's report and can produce requests for further information or changes to layout, access or the approach to evacuation.
Programme accordingly. The realistic sequence is:
- Confirm the height and storey count against the submission drawings.
- Appoint a fire engineer early enough to influence layout, not to describe it.
- Prepare the fire statement on the published form, cross-referenced to the drawings.
- Allow for a consultation response that asks questions.
- Keep the fire statement aligned with any changes made during determination, because a statement that describes a superseded layout is worse than none.
The other reason to get this right is downstream. Gateway One is the planning stage of a three-gateway system. Gateways Two and Three sit under the Building Safety Act 2022 regime with the Building Safety Regulator, and the definition of a higher-risk building there is set by separate regulations made in 2023. The definitions overlap but are not identical, and care homes and hospitals are treated differently between the two regimes. Assuming they are the same causes real problems at the point of construction.
Illustrative example: a seven-storey block of 34 flats over a ground floor gym, top floor slab at 17.8 metres, with a roof-top plant enclosure. The height limb fails. The storey limb, counting seven storeys above ground and ignoring the plant enclosure, is met. The building is caught, and a scheme that assumed otherwise loses its validation date.
Getting the evidence into the application
Put the measurement on a drawing. A section through the building with the ground level datum, the top storey floor level and the dimension annotated is the single most useful thing you can submit, because it lets a validation officer resolve the question in ten seconds rather than emailing you.
Include a short statement in the covering material setting out whether the building is a relevant building and why. Where you conclude it is not, say so explicitly and show the working. Councils are far more comfortable refusing to accept a documented conclusion than discovering an undocumented one.
Where a scheme needs a reviewer with fire engineering competence, the professional directory is one route to finding someone to review a draft before it is submitted.
This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. For specialist technical reports, qualified professional input may be required.
Frequently asked questions
Does Planning Gateway One apply to office buildings?
No. The definition requires the building to contain two or more dwellings or educational accommodation as well as meeting the height or storey test. A tall office block fails the first limb. If that office is later converted to flats and the completed building meets the height or storey test, the conversion application does need a fire statement.
How is the 18 metre height measured?
From ground level to the floor surface of the top storey, not to the parapet, roof or top of a plant screen. A roof-top level containing only plant or machinery is excluded. Where ground levels fall across a site the convention matters, so annotate a section drawing showing the datum, the top storey floor level and the resulting dimension.
Do student halls count?
Yes, where they amount to educational accommodation. The definition places educational accommodation alongside dwellings, so purpose-built student accommodation and boarding accommodation reaching 18 metres or seven storeys is within Gateway One even though the rooms are not dwellings in the ordinary planning sense.
What happens if we submit without a fire statement?
The application is liable to be held invalid, and the validation date moves. On a tall residential scheme that usually costs several weeks at the start of the programme. If there is any doubt about whether the building is caught, submit a statement setting out the measurement and the conclusion so the validation officer can resolve it quickly.
Is a Gateway One fire statement the same as a building regulations submission?
No. The fire statement addresses the fire safety implications that bear on the planning decision, such as site layout, appliance access, water supplies and the principles of the evacuation strategy. Gateways Two and Three under the Building Safety Act 2022 deal with detailed design and construction through the Building Safety Regulator, using a related but separate definition.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.