Balcony construction and combustibility in a description

Balcony materials planning conditions used to be a formality. A line asking for samples of external materials, discharged with a board of samples a year later, and nobody thought about the decking. That changed when the combustible materials restriction in regulation 7 of the Building Regulations 2010 was extended to cover specified attachments, balconies among them, on relevant buildings.

The consequence for architects is that balcony build-up is now a planning-stage decision with elevational effects, and it has to be consistent with whatever the fire statement says.

Why balconies are described in detail now

Amendments made in 2022 extended the restriction on combustible materials in external walls to specified attachments, which include balconies, and extended the building types caught. Verify the current text of regulation 7 and Approved Document B, because this area has been amended repeatedly and the detail matters more than the summary.

For a relevant residential building above the height threshold, the practical position is that timber decking, timber soffits and combustible insulation within the balcony build-up are out. Which removes the finishes that most schemes of the 2010s used.

That is a Building Regulations rule, not a planning rule. But it shows up in planning because the alternatives look different, read differently on an elevation, and change the depth of the balcony assembly. A design officer reviewing a drawing showing timber decking on a twelfth-floor balcony is looking at a drawing that cannot be built.

Where the restriction applies and to what

Scope is the first thing to pin down, block by block.

The restriction applies to relevant buildings, defined by use and height, and to their external walls and specified attachments. A five-storey block in the same development may be outside it while the tower beside it is inside. Check each building separately and record the conclusion on the drawing, because reviewers will ask.

Regulation 7 also lists exempt components, which include items such as window frames and glass, membranes, seals, gaskets, fixings and thermal break materials. That list is why glass balustrades remain available where a timber handrail does not, and it is worth reading rather than paraphrasing.

Decking, soffits and balustrades

Three elements, three different conversations.

The acoustic point in the first row is a real one and it is rarely raised at planning. Open-jointed metal decking transmits footfall noise to the balcony below more readily than a timber deck on pedestals, and residents notice. It is a detailing problem rather than a planning one, and it is better solved at design stage than at handover.

Drainage and detailing consequences

Non-combustible decking changes how the balcony sheds water, and that detail reaches the planning drawings through the threshold.

Open-jointed decking drains through to a waterproofed deck below, which has to fall to an outlet or a slot drain. That assembly needs depth. The depth competes with the accessible threshold requirement at the door, and the usual resolution is a recessed threshold drain and a shallow upstand.

Two things follow for the elevations. The soffit to deck dimension grows, which is visible on a section and on the elevation as a thicker band at each floor. And the drainage outlet or downpipe arrangement becomes an elevational element that has to be drawn rather than left to the contractor.

Get this on the drawings at application stage. A balcony shown as a thin line on a 1:100 elevation becomes a 400 mm band at technical design, and that difference has been the subject of enough amendment applications to be worth avoiding.

The samples condition and how to word it

Most permissions carry a materials condition, and the drafting determines how much freedom you have later.

What works: a condition requiring samples or details of the external materials, including the balcony decking, soffit and balustrade, to be submitted and approved before the relevant part of the works starts, with the development then carried out in accordance with the approved details.

What causes problems: a condition that names specific products. A permission conditioned to a named decking product leaves you needing an amendment when the product is discontinued or the price moves, which on a three-year build programme is likely rather than possible.

So negotiate for performance and appearance rather than product names. Colour, finish, reflectivity, joint pattern and profile depth are the things a design officer actually cares about, and all of them can be specified without naming a manufacturer. A Design and Access Statement is the right place to set out that palette and the reasoning behind it.

Consistency with the fire statement

For a relevant building, the planning application carries a fire statement under Article 9A of the Development Management Procedure Order 2015, and the Building Safety Regulator is consulted on it.

The failure mode is boring and common. The architectural drawings show one balcony build-up, the design and access statement describes a timber-look finish, and the fire statement says all external materials will be of limited combustibility. Three documents, three different buildings.

Reconcile them before submission. One schedule of external materials, referenced by all three documents, with the classification stated for each element. A Fire Statement requires an author with fire-engineering competence, and PlanScope's draft is a starting point for that professional rather than a substitute, so the material schedule has to come from the design team and be consistent across the submission.

While the balconies are being designed, the other question worth settling is whether they will be usable. A Wind Microclimate Assessment tests comfort at balcony level on taller schemes, and a balustrade changed from solid to glass for fire reasons can alter the result. Councils normally expect a suitably qualified author for that work, and professional review is strongly advised.

Changing a product after permission

Products change. The route for dealing with it depends on how the permission was drafted.

1. Where the materials were secured by condition and the condition requires details to be approved, submit the new details for approval under that condition. No amendment application is needed.
2. Where the approved drawings show a specific build-up and the change is slight, an application under section 96A of the Town and Country Planning Act 1990 for a non-material amendment may be appropriate.
3. Where the change alters the appearance in a way that is more than non-material, a section 73 application to vary the relevant condition, or a fresh application, is the honest route.
4. Where the change is driven by a fire requirement and alters the elevations, expect the authority to want the fire statement position updated too.

The judgement about what is non-material belongs to the authority, not the applicant. Ask the case officer informally before choosing a route, because a refused section 96A application wastes more time than a section 73 would have taken.

Enter your postcode on PlanScope to see which reports a scheme with balconies above the height threshold is likely to need.

This is general guidance, not legal advice. Check the current regulation and Approved Document text, and 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.