Non-standard construction

A concrete balcony on a system-built block has not been identified as RAAC. Why is the decade of the block not enough to apply that name?

Because a decade, or the words system-built, does not identify the concrete. RAAC is a particular lightweight panel product. It is not every concrete balcony and not every 1960s or system-built block. The survey should not apply that name unless the panel was actually identified. Do not call woodwool, asbestos cement or dense concrete RAAC. A home survey must not invent a collapse rate or a year when production stopped. Describe the balcony that was seen and say the material is unconfirmed.

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?

Reinforced autoclaved aerated concrete is a specific panel, investigated as that material, not a nickname for any pale soffit. System-built blocks of several decades use dense concrete, timber infill, steel, and other proprietary panels. A balcony can be a concrete slab, a steel tray or a later addition. Age narrows nothing enough to write RAAC on a lender form. The home survey looks at cracks, ponding, stains and the barrier from the flat it was instructed to see. It does not core the soffit as an automatic extra, and a flat inspection does not become a block-wide RAAC study.

If you are worried, say 'concrete balcony, material not identified' and ask a competent person who actually identifies RAAC whether a further look is warranted. Do not helpfully 'upgrade' woodwool, asbestos cement or ordinary dense concrete into RAAC because those words sound serious. Do not add a collapse statistic or a date you think production ended. Those figures are not in this survey and should not be invented. The rating on the balcony, if there is one, is about the defects seen. It is not a materials test, and silence on the name is not a clearance either.

What should you ask your surveyor?

Did you identify RAAC, or is the balcony simply concrete of an unconfirmed type?
What did you actually see: cracks, stains, a soffit, or a label that names the panel?
Will the report avoid RAAC, woodwool and asbestos-cement labels unless they were identified?

What are the typical next steps?

Do not write RAAC on a lender form from the decade alone.
Use 'material not identified' until someone qualified names the panel.
Do not invent a collapse rate or a year production stopped.

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

Is a 1960s concrete balcony RAAC by default?

No. RAAC is not every concrete balcony and not every 1960s or system-built block. The decade is not the name.

If the soffit is woodwool, should I report it as RAAC?

No. Woodwool is not RAAC. Asbestos cement and dense concrete are not RAAC either. Name only what was identified.