A surveyor can flag where a roof or floor might be RAAC and recommend a specialist, but only a suitably qualified chartered building surveyor or chartered structural engineer can assess it properly. This lightweight concrete was used between the 1950s and mid-1990s, and it was not widely used in homes, but buyers of post-war homes with flat roofs are right to ask questions. If you suspect this material in a home you want to buy, you need a professional assessment rather than a standard survey to decide what to do next.
What RAAC is
Reinforced autoclaved aerated concrete is a lightweight building material that was widely used in the UK. It was primarily used between the 1950s and the mid-1990s in roofs and upper floors. You will mostly find it in schools, healthcare facilities, Ministry of Defence properties and civic buildings, as well as some offices and shops.
It is considered to have a lifespan of around 30 years, though it can last longer in well-maintained buildings. Because many installations are now older than that, buyers and owners are right to ask about the condition of these materials today.
The RICS consumer guide, published on 10 February 2026, says a professional assessment determines the best course of action.
Which homes might contain it
The headlines about schools and hospitals have left many home buyers worried, but this material was not widely used in homes. The full extent of its use in the private sector is not definitively known, but there is a clear pattern of where it is most likely to be found. There are reports of it in some social housing and in flats converted from office blocks or public buildings.
Victorian villas and 1930s semis are most unlikely to contain this material unless they have been extended. Traditional houses with pitched, tiled or slated roofs are also unlikely candidates. A standard older property with a normal pitched roof is an unlikely candidate.
Signs of concern include flat or shallow-pitched roofs, especially on post-war homes in estates of similar properties. If you are looking at a property built between the 1950s and the mid-1990s that matches this description, you should be aware of the possibility. Scotland has its own RICS practice alert of February 2026 on RAAC roof panels, so buyers there should ask their surveyor about it.
The table below shows how different property types match the known risk profiles.
|
Property type |
Likelihood of containing the material |
|---|---|
|
Victorian villas and 1930s semis |
Most unlikely unless extended |
|
Traditional houses with pitched, tiled or slated roofs |
Unlikely candidates |
|
Post-war homes in estates of similar properties |
Signs of concern if they have flat or shallow-pitched roofs |
|
Flats converted from office blocks or public buildings |
Reports exist of the material in these buildings |
This is a general guide only, and the history of an individual building can differ.
Why a standard home survey will not settle it
When you buy a home, you usually commission a standard residential survey to check its condition. These follow three RICS levels, but none of these levels involve a specialist structural investigation that can definitively diagnose or test for this specific lightweight concrete. A surveyor can flag where a roof or floor might contain the material and recommend a specialist, but they cannot give you a final answer on their own.
Level 1 describes condition, flags risks and urgent defects, and suits conventional, newer homes in good condition. Inspections take roughly 1 to 2 hours and reports usually follow within about 3 to 10 working days. Level 2 suits conventional homes in reasonable condition, adds advice on repairs and maintenance, and comes as a survey only or a survey and valuation. It is a visual, non-intrusive inspection that takes 2 to 4 hours.
Level 3 is the most detailed and suits older, larger, altered, unusual or run-down homes, or homes you plan to alter. The inspection takes 4 to 8 hours. Because standard surveys are visual and non-intrusive, the surveyor will not cut into panels or carry out laboratory tests. If they see a flat or shallow-pitched roof on a post-war home, they may note it as a risk and advise further investigation.
You should never assume that a standard survey can rule the material out entirely. If you are unsure which level to book, you can read more about types of house survey in the UK. Surveys are sold at a fixed fee quoted up front, driven by the survey level, property value, size, age, complexity and location.
The table below outlines the expected costs for these standard inspections.
|
Survey type |
Typical price range |
|---|---|
|
Level 1 |
£300 to £450 |
|
Level 2 |
£400 to £950 |
|
Level 3 |
£600 to £1,500 or more |
These are typical 2026 ranges rather than quotes, and local fees will differ.
Who should check for RAAC
If a standard survey flags a risk, or if you suspect the property falls into the at-risk category, you must bring in the right professional. Only a suitably qualified chartered building surveyor or chartered structural engineer can assess it properly. RICS advises taking advice from a chartered building surveyor or chartered engineer, and specifically recommends a structural engineer who is a member of the Institution of Structural Engineers.
When gathering prices for a standard survey to begin the process, make sure you get two or three like-for-like quotes that state:
- The specific RICS survey level being offered.
- Whether a valuation is included in the fixed fee.
- The expected turnaround time for the final report.
- Confirmation of the surveyor's experience with the local area.
You should check your chosen specialist belongs to a regulated professional body before you instruct them. RICS regulated firms must have a complaints handling procedure, give consumers free access to an independent alternative dispute resolution provider, and hold professional indemnity insurance. You can confirm their credentials on the RICS Find a Surveyor service by looking for AssocRICS, MRICS or FRICS after the surveyor's name.
You must not attempt to check the property for this material yourself. Do not look closely at roof surfaces or ceilings, and never score or cut into building materials to see what is underneath. RICS cautions that some textured plaster surfaces could contain asbestos, which is dangerous if disturbed. Do not enter lofts, lift drain covers, or carry out your own structural checks. If you are unsure, ask for a professional assessment.
What a professional assessment can lead to
When you hire a chartered structural engineer or a chartered building surveyor, they will inspect the suspected areas safely. Their professional assessment determines the best course of action for the property. Finding the material does not automatically mean the building is unsafe, but it does mean a plan is required.
According to RICS guidance, the options following an assessment generally fall into three categories. The expert will recommend the one that matches the current condition of the panels.
- Regular monitoring to check for signs of deterioration over time if the panels are currently intact.
- Reinforcement or repair to support the existing structure and prevent future failure.
- Replacement of severely deteriorated panels where repair is no longer a viable option.
If the recommendation is replacement, this will involve significant building work. You will need to get detailed repair quotes from specialist contractors to understand the financial impact. You can then use these findings to decide whether to proceed with the purchase, renegotiate the price with the seller, or walk away entirely.
RAAC, mortgages and valuation
A mortgage valuation is not a survey. It is a limited check for the lender's benefit to confirm the property is worth the money you want to borrow. If you are relying solely on a mortgage valuation, you are making a common mistake, as the valuer will not conduct a detailed condition check.
If a valuer suspects the presence of this lightweight concrete, they will not make any inspection of the condition of the elements themselves. Instead, the valuer may request an independent specialist report before they can confirm the valuation for the lender. This may delay your mortgage application.
Lending policies vary significantly across the market. RICS states that it is not necessarily the case that a property with this material is not suitable for a mortgage.
RAAC and home insurance
It helps to understand how home insurance policies treat building materials that degrade over time. Household insurance policies generally cover insurable events such as storm, fire or flood. They do not cover the presence of a material known to fail.
The Association of British Insurers says the replacement of RAAC is not likely to be covered. If a roof made of this material is still performing as designed, a claim to replace it is unlikely to succeed. Insurance is designed to protect against sudden and unexpected damage, not the natural end of a building material's lifespan.
If you know this material is present in a property you own or are buying, you should tell your insurer. If you are buying a flat, you should also ask your conveyancer to check the building insurance policy held by the freeholder or management company.
What to do while you wait
If your residential surveyor flags a potential issue and you need to wait for a structural engineer, you must manage the transaction carefully. Book the specialist assessment as soon as possible, so that the delay is as short as possible. Let your estate agent know exactly why there is a delay, so they can keep the seller calm and prevent the property going back on the market.
Do not try to renegotiate the purchase price without repair quotes. A seller is unlikely to accept a price reduction based on a suspicion alone. Wait for the chartered structural engineer to produce their report, and then get fixed quotes for any required monitoring, reinforcement or replacement.
Keep your conveyancer fully informed. They will need to read the specialist report to understand if there are any legal implications, especially if the property is a leasehold flat and the roof is shared with other residents. Under the Consumer Rights Act 2015, a service must be carried out with reasonable care and skill. Services arranged online or by phone normally carry a 14-day cooling-off period, but if you ask for the work to start inside it you pay for what has been done.
Common questions
Can a standard survey rule out the material entirely?
No. A standard home survey is a visual inspection and does not involve the destructive testing needed for a definitive diagnosis. A surveyor can flag where a roof or floor might contain the material, but they will advise you to get a professional assessment from a specialist to be certain.
Should I check my loft or flat roof myself?
You must never attempt to check for this material yourself. You should not look closely at roof surfaces or ceilings, and you must never score or cut into building materials. RICS cautions that some textured plaster surfaces could contain asbestos, so if you are unsure, ask for a professional assessment.
Is RAAC common in private houses?
It was not widely used in individual homes. There are reports of it in some social housing and in flats converted from office blocks or public buildings. The full extent of its use in the private sector is not definitively known, but traditional pitched roof houses are unlikely candidates.
Will I be able to get a mortgage if the material is found?
Lending policies vary between different banks and building societies. RICS confirms that it is not necessarily the case that a property with this material is unsuitable for a mortgage. The valuer may request an independent specialist report to satisfy the lender before they approve the loan.
Does a mortgage valuation check for RAAC?
A mortgage valuation is a limited check for the lender and not a detailed survey. The valuer will not inspect the condition of the material themselves. If they suspect it is present, they may request an independent specialist report.
Your next steps
Finding out a property might contain this lightweight concrete is stressful, but following the correct process will protect your investment. Keep your conveyancer and the estate agent updated while you gather the details.
- Note the age and style of the property, and tell your surveyor if it is a post-war home with a flat or shallow-pitched roof.
- Commission a Level 2 or Level 3 survey so a residential surveyor can inspect the general condition and flag any obvious risks.
- Hire a chartered building surveyor or a chartered structural engineer if the initial survey recommends a specialist assessment.
- Use the findings from the professional assessment to get repair quotes from specialist contractors.
- Decide whether to proceed, renegotiate the purchase price with the seller, or walk away from the transaction.
If you are ready to book a standard residential survey to assess the overall condition of the property, you can find a surveyor near you to get started.
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