Leasehold
Where a report pairs render on a carrier board with a flat elevation, what stays open about the insulation behind the board, which render hides?
What stays open is the insulation behind the carrier board, which the render hides, and everything else in that build-up on the flat elevation. The report paired a rendered carrier board with the elevation it could see. It has not decided what sits behind the board, whether any insulation is present, or how the wall is fixed back to the frame. A home survey does not open render to sample the layers. The visible coating is not a verdict on the concealed insulation or on fire performance of the external wall.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Render is a surface finish. A carrier board is the sheet it is applied to. Insulation, if it is there, can sit behind that sheet, between rails, or in a different position the eye cannot map from the street. The surveyor can comment on cracks, staining, hollow-sounding areas and how the elevation meets windows and balconies. Those are surface observations. They do not identify the product, the thickness or the cavity. Pairing the words in one note is a description of the outside, not a specification of the wall.
Ask the solicitor for the external-wall information the building holds: as-built drawings, any fire assessment, and what the landlord says the elevation is made of. Do not let the render colour stand in for that pack. A lender may ask its own questions about the external wall of a flat. The home survey has not answered them and has not sampled the insulation. If a specialist facade inspection is required, instruct it separately and keep it apart from this visual note.
What should you ask your surveyor?
- What of the rendered carrier board was visible on the elevation?
- Does the report stop short of naming the insulation behind the board?
- Were any openings made, or is the build-up entirely concealed?
What are the typical next steps?
- Treat the render note as a surface observation only.
- Ask the solicitor for the external-wall information pack.
- Keep any later facade inspection separate from this survey.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a hairline crack in the render identify the insulation?
No. A hairline crack is a mark in the finish the surveyor could see. It does not name the board, the insulation or the fixings. The visit did not open the crack or sample the wall. Pass the crack to anyone later asked to assess the elevation, but do not call it evidence of what the render is hiding.
Should the leaseholder pay for opening the wall?
Who pays depends on the lease and on what the landlord agrees, not on this report. The survey should not invent a repairing duty, and it has not costed any opening. Your solicitor can match the elevation to the lease. Until there is a proper instruction, the insulation behind the board stays unknown.