Fire statement for a change of use rather than new build

A fire statement is required on a change of use application where the development involves a building that will contain two or more dwellings or educational accommodation and the building is 18m or more in height, or has seven or more storeys. Article 9A of the Development Management Procedure Order 2015 ties the duty to the finished building, not to whether you are building something new, so an office to residential conversion of a tall building engages Planning Gateway One in exactly the same way a new block would. Fire statement change of use cases are harder than new build, because the construction you have to describe already exists and nobody knows what is inside it.

The Health and Safety Executive is the statutory consultee, and its comments come back on the planning application.

When a change of use engages the fire statement duty

Three questions decide it. Does the proposal create two or more dwellings or educational accommodation in the building. Will the building, as proposed, reach 18m or seven storeys. Is the application a type to which Article 9A applies.

Height is measured to the floor level of the top storey, not to the ridge or the parapet, and the measurement is taken from ground level. On a conversion that matters, because an existing building whose top occupied floor sits just under 18m may cross the threshold if a roof-level extension adds a storey. Adding a single floor to a six-storey building takes you into the regime even though the existing building was outside it.

Permitted development conversions are the trap. A prior approval under Class MA of Part 3 does not carry the Article 9A fire statement duty in the way a full application does, so a landlord converting under permitted development may reach completion without the planning-stage fire scrutiny, then meet the Building Safety Act 2022 gateways at building control. That is a sequencing problem rather than an escape, and it usually surfaces as a redesign.

A Fire Statement is a planning document with a prescribed form and prescribed content. It is not a fire strategy, though the two overlap and the second is usually needed to write the first.

Identifying whether the building is a relevant building

Work from the proposed drawings and measure carefully, then record the measurement on a section drawing with the datum shown.

The common errors are measuring to the top of the parapet, measuring from the lowest point of a sloping site rather than the relevant ground level, counting a plant enclosure as a storey, or not counting a mezzanine that works as one. Where a building is within a metre of the threshold, get the measurement surveyed rather than scaled, because the consequence of being wrong is an invalid application or a fire statement submitted that was never needed.

Basement storeys count in the storey total in the way the legislation sets out, and a conversion that creates habitable rooms below ground raises separate questions about means of escape. Those belong in the fire strategy and, where excavation is involved, alongside the Basement Impact Assessment.

Existing construction and unknown build-ups

Here is the real difference from new build. On a new building, the fire engineer specifies the construction and then describes it. On a conversion, the construction is already there and has to be discovered.

The unknowns that matter are the external wall build-up and any combustible material within it, the compartmentation between floors and between the proposed dwellings, the structural frame and its fire resistance, the condition of existing fire stopping at service penetrations, and whether any cladding, insulation or spandrel panel system has been added since the building was completed. Record drawings, where they survive, are frequently wrong about all of this.

An honest fire statement for a conversion says what is known, what is assumed and what will be confirmed by intrusive survey, and it says which of those assumptions the design depends on. A statement that simply asserts compliant compartmentation on a 1970s office building is making a claim it cannot support, and the regulator will say so.

Intrusive survey and its planning implications

Intrusive opening-up is the only way to establish the external wall build-up with confidence. It means cutting inspection openings at a sample of locations, recording the layers, and sometimes taking material samples for testing.

Two planning consequences follow. First, the survey usually has to happen before the application, because the design response depends on what is found, and a fire statement built on assumptions that the survey then contradicts means a revised statement mid-determination. Second, where the building is listed or in a conservation area, opening-up works to a listed building may themselves need listed building consent, and that application has to run first.

Access is the practical obstacle. A tenanted office building, a vacant building with no power, or a building where scaffold is needed for high-level openings all add weeks. Price the survey and the access together.

Where the survey finds combustible insulation or a cavity barrier failure, the scheme changes: recladding, additional compartmentation, or a different internal layout to shorten escape routes. That is a cost and programme event, and it is better discovered before the planning fee is paid.

Drawings required where none exist

Article 9A asks for the fire statement on the prescribed form, and the form asks for information that has to be drawn. On a conversion with no usable record drawings, the measured survey comes first.

What the statement needs to be able to reference: existing and proposed floor plans at a scale that shows compartment lines, a section showing the height measurement, a site plan showing fire service access routes and the position of hydrants, a plan showing the location and dimensions of the fire appliance hardstanding, and a layout showing the means of escape with travel distances annotated.

Fire service access on a conversion is often the binding constraint. A building that worked as an office with a single access point may not satisfy the access and water supply expectations for residential use, and the solution can require highway works or the loss of parking, both of which feed back into the Transport Statement and the site layout.

What the regulator asks of a conversion

The Health and Safety Executive, as Gateway One consultee, looks for the fire safety matters that planning can actually influence: the site layout, access for fire appliances, water supplies for firefighting, the siting of the building and the arrangement of escape and evacuation at a strategic level.

For a conversion its questions concentrate on what the existing building constrains. Whether a single stair arrangement is being retained and how it is justified. How the existing core, risers and lobby arrangement supports the proposed evacuation strategy. Whether the external wall is being addressed or left as found. Whether fire appliance access can reach within the required distance of a dry riser inlet given the existing site boundaries.

Answer those directly. A statement that describes the proposed sprinkler specification at length and the site access in two lines is answering the building control question rather than the planning one. The companion Fire Safety Strategy is where the detailed engineering belongs, and a BS 9991 strategy is a fire-engineering document that a competent fire engineer must prepare.

Sequencing survey, statement and application

Run it in this order and the programme holds.

1. Measure the building and confirm whether the threshold is crossed, with the section drawing as evidence.
2. Commission the intrusive survey and any listed building consent needed to carry it out.
3. Appoint the fire engineer to produce the strategy, working from survey findings rather than assumptions.
4. Let the architect resolve layout, core and access changes that the strategy requires.
5. Draft the fire statement on the prescribed form, cross-referenced to the strategy and the drawings.
6. Submit, and expect a consultee response that asks for something the strategy covers but the statement did not repeat.

Buildings just below the threshold still attract scrutiny, and fire evidence for a building just below the threshold covers what to submit voluntarily. Where habitable rooms go below ground, safe egress from habitable basement rooms is the related question.

A fire statement and a fire safety strategy are documents a professional with fire-engineering competence must prepare, under the Building Safety Act 2022 framework and Article 9A. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.