Eighteen metres, seven storeys and Planning Gateway One
Reach 18 metres or seven storeys in a residential building and a fire statement becomes a validation requirement. Here is how the tests are measured and what to submit.
Two numbers decide whether your application needs a fire statement and a consultation with the Health and Safety Executive: 18 metres in height, or seven storeys. Reach either one, in a building containing two or more dwellings or providing educational accommodation, and the scheme is a relevant building for planning purposes. The 18 metres gateway one threshold is not a design guideline. It is a validation requirement, and an application for a relevant building submitted without a fire statement on the prescribed form is invalid.
The requirement comes from Article 9A of the Development Management Procedure Order 2015, introduced as part of the framework built around the Building Safety Act 2022. Planning Gateway One is the first of the three gateways, and it sits in the planning system rather than in building control.
How the height and storey tests are measured
Height is measured from ground level to the floor surface of the top storey. Not to the ridge, not to the top of the parapet, and not to the top of the lift overrun. Designers who measure to the roof are the ones who conclude they are safely under.
Storeys are counted, and storeys consisting only of plant or machinery are disregarded in the count. Basements and storeys below ground level are treated separately from the above ground count, which matters on sloping sites where one elevation has an extra storey at the low end.
The definitions are prescriptive and they are the kind of thing an officer checks against the regulations rather than against custom, so read the current wording before you conclude which side of the line a scheme falls on. Where a site slopes, establish the ground level datum explicitly on the section drawing, because an assumed datum that shifts by 400mm can move a building across the threshold.
What a relevant building means for your submission
For a relevant building, the application must be accompanied by a fire statement on the form published by the Secretary of State, and the Health and Safety Executive becomes a statutory consultee on the application.
That has three programme consequences.
- Validation will fail without the statement, so the eight or thirteen week clock does not start.
- The consultation adds a round trip that has to be built into the determination period, and the Executive's response may ask for further information before it can give substantive advice.
- Design decisions that used to be left to the technical design stage, such as fire service access and water supply, have to be settled at planning stage.
The statement is not a full fire engineering strategy. It addresses the fire safety matters that relate to land use planning: site layout and the access a fire appliance needs, water supplies for firefighting, the principles of the external wall construction, means of escape and the evacuation strategy in principle, and the position of fire mains and access points.
Who has to write it
A Fire Statement requires an author with the necessary fire engineering competence. This is one of the report types where a competent professional is legally required rather than merely advisable, because the statement sits inside the Building Safety Act 2022 framework and Article 9A of the Development Management Procedure Order 2015, and a statement written by someone without that competence is likely to attract a request for further information rather than substantive advice.
PlanScope can draft the structure and populate the policy and procedural sections of a fire statement, and that draft is a starting point for the fire engineer rather than a substitute for one. The same applies to a Fire Safety Strategy prepared to BS 9991 or BS 9999, which is a fire engineering document in its own right. If you need a reviewer, the professional directory is the route for review and sign off.
The statutory consultee and what it looks for
The Executive's role at this gateway is advisory. It reviews the fire statement and gives advice to the local planning authority, which must have regard to it. Councils rarely grant permission for a relevant building where that advice is unresolved.
Responses that ask for more information, rather than giving substantive advice, are the usual cause of delay. The pattern is consistent: the statement describes the building but not the site, or it asserts compliance without explaining how the layout delivers it.
Four things reduce that risk.
- Show fire appliance access on the site layout, with dimensions, turning provision and the distance from the appliance standing position to the building entrances and to dry or wet riser inlets.
- Show the firefighting water supply, naming the hydrant positions or the tank and pump arrangement, and say who has confirmed the flow.
- State the evacuation strategy in principle, and where the design relies on a single stair, say so explicitly and explain the basis.
- Describe the external wall construction in principle, including balconies and any combustible elements, rather than deferring the whole subject to Gateway Two.
Say what is fixed and what is still to be designed. A statement that distinguishes settled principles from matters reserved for the later gateways reads as a competent document. One that is silent on the distinction invites questions.
Interaction with the later gateways
Gateway One is planning. Gateway Two is the building control approval application made to the Building Safety Regulator before construction begins on a higher risk building, and Gateway Three is the completion stage. The regulator sits within the Health and Safety Executive.
The definitions are related but not identical, which is a source of confusion. The planning definition of a relevant building includes educational accommodation, and the higher risk building definition used for the later gateways is drawn for a different purpose. Do not assume that clearing Gateway One means the building will be treated the same way at Gateway Two.
What carries across is the substance. Decisions taken at planning stage about massing, core position, stair provision and site access constrain what the later gateways can accept, and changing them after permission is granted is expensive. Where a scheme reaches this scale, other consultees and requirements arrive as well, which we set out in statutory consultees that appear as a scheme grows.
Schemes that cross the threshold during design
The awkward cases are the ones that approach the line and then cross it.
| Change during design | Effect on the threshold |
|---|---|
| Adding a plant enclosure at roof level | Usually none, since plant only storeys are disregarded |
| Adding a top floor apartment | Can add a storey and push height above 18 metres |
| Raising ground level for flood resilience | Changes the datum and can lower measured height |
| Excavating to create a lower ground floor | Changes the storey count at one elevation |
| Increasing floor to ceiling heights across the block | Can cross 18 metres without changing the storey count |
Test the threshold at every design freeze, and record the measured height and storey count on the drawing set. A one line note on the section saying height to top storey floor level, with the figure, saves an argument at validation.
If a scheme crosses the line late, the honest response is to treat it as a fire engineering input to the design rather than a document to be added at the end. That may mean a second stair. The expectation of a second staircase in new residential buildings above 18 metres has been introduced through changes to Approved Document B with transitional arrangements, so take the current position from the published guidance rather than from a project you worked on two years ago, because the core arrangement is a planning matter as well as a building regulations one.
In London, schemes of this height also engage referral thresholds and additional policy, which we cover in mayoral referral thresholds for London residential schemes.
Draft your fire statement structure on PlanScope and then send it to a fire engineer for review and sign off. 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, and a fire statement is one of them. This is general guidance rather than legal advice, so check the current definitions and requirements with your local planning authority and a competent fire engineer.
Frequently asked questions
How is the 18 metre height measured?
From ground level to the floor surface of the top storey, rather than to the ridge, the parapet or the top of a lift overrun. Designers who measure to the roof often conclude wrongly that a scheme falls below the threshold. On a sloping site, fix the ground level datum explicitly on the section drawing and note the measured height on the set.
What happens if I submit without a fire statement?
The application is invalid, so the determination period does not begin. A relevant building application must be accompanied by a fire statement on the form published by the Secretary of State, under Article 9A of the Development Management Procedure Order 2015. Councils check this at validation, before any assessment of the scheme takes place.
Who can prepare a fire statement?
Someone with the necessary fire engineering competence. This is a report type where a competent professional is legally required rather than simply recommended, because it sits within the Building Safety Act 2022 framework. A draft prepared without that competence tends to attract a request for further information instead of substantive advice from the Health and Safety Executive.
Is the Health and Safety Executive response binding?
Its role at Planning Gateway One is advisory, and the council must have regard to the advice rather than follow it. In practice councils rarely grant permission for a relevant building while that advice is unresolved. The common cause of delay is a response asking for more information because the statement describes the building but not the site.
Does clearing Gateway One mean the building satisfies the later gateways?
No. Gateway Two is the building control approval application to the Building Safety Regulator before construction, and Gateway Three is the completion stage. The definitions used at each stage are drawn for different purposes, and the planning definition of a relevant building includes educational accommodation. Decisions on massing, cores and access still constrain the later stages.
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.