Combustible materials rules and planning elevations
Regulation 7(2) restricts combustible materials in the external walls and specified attachments of relevant buildings. Here is what that does to a planning material palette, and how to draft the condition.
Regulation 7(2) of the Building Regulations 2010 is a Building Regulations matter, and it still decides what you can draw on a planning elevation. It restricts the materials that may be used in the external walls and specified attachments of a relevant building to those achieving European reaction to fire classification A2-s1,d0 or A1. Timber cladding, timber balcony decking, most render systems built over combustible insulation and a long list of decorative materials do not meet it. If those materials appear on a consented elevation and the building turns out to be caught, the scheme cannot be built as approved.
The planning risk is therefore a coordination risk. A permission conditioned to a named cladding product that cannot lawfully be installed is a permission that needs varying before a brick is laid.
What the restriction covers
The requirement applies to materials that become part of an external wall, or part of a specified attachment, of a relevant building. It is expressed as a classification requirement rather than a list of banned products, which matters because a material can pass or fail depending on the system it is tested within.
Regulation 7(3) exempts a defined set of components from the requirement, and that list is where most of the design freedom sits. It covers items such as cavity trays, window and door frames and glass, electrical installations, membranes, sealants, gaskets, fixings, sills and flashings. The list is specific, and something not on it is not exempt because it is small.
Read the current consolidated text before advising on a scheme. Regulation 7 has been amended more than once since 2018, including changes to the buildings caught, the treatment of metal composite material and the extension of the restriction to specified attachments. Working from a summary written a few years ago is how errors reach drawings.
Which buildings are caught
The definition of a relevant building combines a height threshold with a list of uses, and it is the part of the regulation that has moved most since it was introduced. The current definition sits in regulation 7 and the associated definitions in the Building Regulations 2010 as amended, and it should be read in its current form for every project.
What has stayed constant is the method of measuring. Height is taken from ground level to the floor surface of the top storey, and a top storey consisting exclusively of plant rooms is left out of account. That is the same measuring convention used elsewhere in the fire safety framework, and it is why a roof top plant enclosure can sit above the measured height without changing it. Other duties cluster around the same dimension, which is why the height that separates dry and wet risers is worth checking on the same section drawing.
Two practical consequences. A scheme sitting a few hundred millimetres either side of a threshold needs the measurement fixed and recorded early, because the material palette depends on it. And a mixed use block can contain caught and uncaught parts, so the answer is building by building rather than site wide.
What counts as part of the external wall
This is where arguments happen. The wall means far more than the outer skin. It takes in the insulation, the sheathing, the cavity barriers, the support system and anything else forming part of the construction, which is why a non-combustible rainscreen over combustible insulation does not satisfy the requirement.
Items to check on a typical residential elevation.
- Cladding boards, battens and support rails
- Insulation in the cavity or on the sheathing face
- Render carrier boards and insulated render systems
- Soffits and reveals to window and door openings
- Spandrel panels and infill panels within a curtain wall
- Decorative features such as fins, brise soleil frames and parapet copings
Whether a component forms part of the external wall is a technical judgement for the designer and building control body, and it needs to be resolved before the planning elevations are fixed, not afterwards.
Balconies, shading and solar panels
Specified attachments bring the restriction outside the wall line. Balconies, solar shading devices and solar panels attached to an external wall of a relevant building are within scope.
The effect on design is immediate. Timber decking on a balcony, timber soffits under a balcony slab, composite decking boards and timber pergola structures on terraces all become problems. So do some proprietary balcony systems whose drainage and finish layers were never tested to the required classification as installed.
Illustrative example: a consented elevation showing projecting balconies with timber decking and a horizontal timber screen to the side returns. The visual intent is straightforward to keep with an aluminium decking board in a timber tone and a perforated metal screen with the same rhythm of verticals. The elevation looks materially the same and the specification changes completely, which is exactly the kind of substitution a condition should allow for. The interaction between balcony design and external fire spread is covered further in balconies, external walls and fire spread.
The effect on a planning material palette
Planning officers assess appearance. They ask for natural materials, warmth, texture and variation, and the palettes they prefer on a tall residential block are frequently the ones regulation 7(2) rules out.
The conflict is manageable if it is faced at design stage. Metal cladding in timber-effect finishes, terracotta rainscreen, fibre cement, glazed brick slips, anodised and powder coated aluminium and non-combustible mineral boards all give an officer something to work with. What does not work is promising timber at committee and substituting metal at technical design, which reads to a planning officer as a material dilution of the approved scheme and can generate an enforcement conversation.
Where the site is in a conservation area or the setting of a listed building, say so in the fire and materials narrative, because the heritage officer's expectations and the regulation pull in opposite directions and the tension is better acknowledged than discovered.
Conditioning materials without painting yourself into a corner
The drafting of the materials condition decides how much pain follows. Three patterns work.
- A condition requiring samples of materials to be approved, described by type, finish and colour rather than by manufacturer and product code
- A condition requiring a materials schedule that states the reaction to fire classification alongside each material, which forces the coordination at the right moment
- A condition permitting substitution of a material of equivalent appearance where required to comply with Building Regulations, with written agreement
The third is the useful one, and officers will often accept it where the reason is explained. Without it, a substitution needs a non-material amendment under section 96A of the Town and Country Planning Act 1990 or a variation under section 73, with the delay and uncertainty that brings.
Sample panels are worth building. A 1.2m by 1.2m panel of the actual system, on site, resolves more disputes about appearance than a folder of swatches, and it is the point at which the fire classification documentation and the visual approval meet in one place.
Getting the elevation and the specification to agree
| Submission item | What it should state |
|---|---|
| Elevations | Material zones keyed to a schedule, not annotated with product names alone |
| Materials schedule | Each material with finish, colour reference and reaction to fire classification |
| Fire statement | The measured height, the top storey reference level and whether the building is a relevant building |
| Section details | Wall build-up showing insulation, cavity and support system for each zone |
| Balcony details | Deck finish, soffit treatment and screen material with classifications |
A Fire Statement is required at Planning Gateway One for relevant buildings under the Building Safety Act 2022 framework and article 9A of the Development Management Procedure Order 2015. It must be prepared by someone with the necessary fire engineering competence, which is a legal requirement rather than a recommendation, and an AI-assisted draft is a starting point for that professional rather than a substitute for them. The same is true of a Fire Safety Strategy prepared to BS 9991 or BS 9999.
Where the block sits above commercial units, the material palette question is entangled with escape strategy and compartmentation, and fire strategy for a residential block above commercial units covers that overlap.
This is general guidance, not legal advice; check the current text of the Building Regulations and the position with your local planning authority, your building control body and a qualified fire engineer 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
What does regulation 7(2) actually require?
That materials becoming part of an external wall or a specified attachment of a relevant building achieve European reaction to fire classification A2-s1,d0 or A1. It is a classification requirement rather than a list of banned products, and regulation 7(3) exempts a defined set of components such as window frames, membranes, gaskets, fixings and flashings.
How is the height measured?
From ground level to the floor surface of the top storey, with a top storey consisting exclusively of plant rooms left out of account. That convention means a rooftop plant enclosure can sit above the measured height without changing it. Fix and record the measurement early, because the material palette depends on which side of the threshold you fall.
Is a non-combustible rainscreen over combustible insulation acceptable?
No. The external wall includes the insulation, sheathing, cavity barriers and support system, not just the visible outer skin. A compliant outer board over insulation that fails the classification does not satisfy the requirement. Whether a given component forms part of the external wall is a technical judgement for the designer and building control body.
Do balconies come within the restriction?
Balconies, solar shading devices and solar panels attached to an external wall of a relevant building are specified attachments and are within scope. That rules out timber decking, timber soffits and many composite boards, and it catches proprietary balcony systems whose finish and drainage layers were not tested to the required classification as installed.
How should the materials condition be worded?
Describe materials by type, finish and colour rather than by product code, require a schedule stating the reaction to fire classification for each material, and include permission to substitute a material of equivalent appearance where Building Regulations compliance requires it, subject to written agreement. Otherwise a substitution needs a section 96A or section 73 application.
Who has to prepare the fire statement?
Someone with the necessary fire engineering competence. The fire statement required at Planning Gateway One under the Building Safety Act 2022 framework and article 9A of the Development Management Procedure Order 2015 is a professional document, and a drafted starting point does not replace that competence or the professional's sign-off.
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.