External wall materials and the samples condition

A samples condition on a residential block is no longer only about how the brick looks. Since the external materials condition fire question became live, the same condition has to be discharged against a specification that also satisfies regulation 7 of the Building Regulations 2010 and, for higher-risk buildings, the Building Safety Regulator. Approve a material on appearance that the fire route will later reject and you have bought yourself a substitution, a redesign and a delay.

What the samples condition controls

The standard wording requires that no development above a stated level takes place until samples or details of the external materials have been submitted to and approved in writing by the local planning authority, and that the development is then carried out using the approved materials.

Planning is controlling appearance: colour, texture, module, bond, mortar, reveal depth, and how the elevation reads in the street. It is not controlling fire performance, structural adequacy or thermal performance, all of which belong to the Building Regulations regime.

That division sounds tidy. It stops being tidy the moment a material passes one test and fails the other, which on taller residential buildings happens often enough to plan for.

Fire performance and planning appearance

Regulation 7(2) of the Building Regulations 2010 restricts the materials that may be used in the external walls of relevant buildings above 18 metres, requiring the higher European reaction to fire classifications. The scope was extended in 2022 to further building types, and metal composite material of the kind implicated in past failures is prohibited irrespective of height. Check the current text of regulation 7 and Approved Document B rather than a summary, because this area has been amended repeatedly.

The practical effect on the planning side is a narrowing of the palette. Timber cladding, some rainscreen systems, certain insulation products and many decorative panels drop out of contention on a tall residential block. What remains is brick and brick slip, masonry, some metals, terracotta, concrete and glass, each with its own appearance consequences.

So the sensible sequence is to fix the material palette against the fire constraint first and then design the elevation, rather than designing an elevation and hoping the specification will follow. And on any building at or above 18 metres or seven storeys with two or more residential units, the Fire Statement submitted with the application under Article 9A of the Development Management Procedure Order 2015 should already have described the external wall approach.

Substitution after permission

Substitutions arrive from three directions: the fire specification rules a product out, the product is discontinued or unobtainable, or the cost plan demands a cheaper alternative. Each is handled the same way.

Ask two questions. Does the approved drawing or the decision notice tie the development to a named material? And is the change one an ordinary observer would notice from the street?

Section 96A is quick and carries no appeal right if refused. Section 73 takes eight weeks and produces a new permission. Choosing the wrong one wastes more time than picking the slower route in the first place.

Evidence to submit with the condition discharge

A discharge submission that gets approved first time usually contains more than a photograph. Officers want to see the material in context and at scale.

• A sample panel built on site, commonly at least one square metre, showing the brick or cladding with the intended mortar, bond and joint profile, retained until practical completion.
• Manufacturer's technical data sheets naming the product, the range and the finish, not just the family.
• The reaction to fire classification for each external wall material, with the test standard stated.
• Elevational drawings keyed to the materials schedule, so each area of the facade is identified.
• Photographs of the panel in daylight, with a scale rule and a note of the orientation.

Where the site is in a conservation area or affects the setting of a listed building, add a short justification tying the choice to the local vernacular. Conservation officers respond to evidence about weathering and colour range, less so to product names.

Illustrative example: a nine-storey block of flats consented with a buff brick and a timber-clad top storey. At specification stage the timber is ruled out by the fire route. The replacement, a buff terracotta rainscreen, reads differently in the elevation because the module and the shadow gaps change. The case officer accepts it under section 73 with revised elevations, and the sample panel is built twice, once in each material, so the comparison is on the record.

Interaction with the building control route

For a higher-risk building the Building Safety Regulator controls the construction phase, and the change control procedure that applies after Gateway Two approval is separate from anything the local planning authority does. A material change agreed with the case officer does not bind the regulator, and vice versa. What Gateway Two requires before construction starts should be understood before the planning discharge is drafted, because the specification submitted to each body should be the same specification.

Keeping the two aligned is partly a records problem. The information trail that the building safety regime expects, and what planning contributes to the golden thread, means the approved samples, the data sheets and the classification evidence should be filed as a set rather than scattered across email.

Design changes driven by fire strategy rarely stop at the facade. A revision that moves a core or adds a stair has elevational consequences too, which is why the debate about second staircases above 18 metres reached the planning drawings as well as the fire strategy.

Drafting a workable condition

Applicants can offer condition wording, and on materials it is worth doing. A condition that simply says "samples shall be approved" invites a discharge cycle with no defined content.

Better wording states what must be submitted: a materials schedule keyed to the elevations, product data sheets, reaction to fire classification where regulation 7 applies, and a sample panel to be erected on site and retained. It also sets the trigger sensibly, at first floor slab or before the external walls are constructed rather than before any development at all, so that groundworks are not held up.

A second improvement is to ask for approval of a materials palette with named alternates rather than a single product. Where the fire specification is still developing, listing an acceptable range of finishes at the planning stage saves an amendment later, and officers are usually willing if the range is tight and the appearance consistent.

One thing to resist is a condition requiring the council to approve fire performance. That is not a planning matter, the case officer is not qualified to judge it, and a condition on it fails the relevance and enforceability tests in Planning Practice Guidance.

Where a building is higher-risk, the fire statement and the fire safety strategy are documents a competent fire engineer must prepare. A drafting tool can structure them and assemble the policy references, and a suitably qualified professional is legally required to take responsibility for the content. PlanScope drafts the planning documents and routes them to a reviewer through its professional directory.

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.