27 Jun, 2025/ by Surveyor Local /Guides, Property defects
Buying a home built between the 1950s and 1990s? You need to know about RAAC, a building material that has caused serious structural concerns across the UK. Here is everything you need to know about identifying, managing and dealing with its presence.
What does RAAC stand for?
RAAC stands for Reinforced Autoclaved Aerated Concrete. It is a lightweight concrete material containing bubbles created through a chemical reaction. Mixed with concrete, slag and aluminium, with steel reinforcement rods, RAAC was widely used from the 1950s through the 1990s for quick, cost-effective building construction.
The key issue for anyone buying a property is that RAAC has a lifespan of approximately 30 years, meaning many buildings containing it are now past their safe usage period.
How to identify RAAC in properties
RAAC was commonly used for roof construction, wall structures, floors, beams and planks across a wide range of building types from schools and hospitals to residential homes and commercial premises. Buildings most likely to contain it are those constructed during the post-war building boom, when speed and cost were the priority.
The presence of RAAC is not always obvious from visual inspection alone, which is why specialist testing and assessment are often required to confirm it.
Why RAAC poses serious structural risks
The lightweight design that made RAAC popular is precisely what makes it problematic today. Moisture infiltrates the bubble structure, causing decay and making the material crumbly over time. Water also causes the steel reinforcement rods within RAAC to rust, which compromises the structural integrity of ceilings, beams, floors and walls. In buildings with significantly deteriorating RAAC, there is a genuine risk of structural failure, particularly in roofs.
Even protective coatings such as bituminous paint have a limited lifespan and are subject to their own deterioration.
Is the problem resolved?
Despite reduced media coverage since the initial 2023 headlines around school closures, RAAC remains a significant ongoing issue. Remediation is expensive, time-consuming and structurally complex. Many buildings still require assessment and active management of the risks involved.
Recent guidance shows both the ongoing challenges and some progress, including cases where alternatives to demolition are being explored and examples of successful RAAC remediation work.
What type of inspection do you need?
If you are buying a building constructed between 1950 and 1990 and suspect RAAC, you need a professional assessment to understand the risks.
A RICS Level 2 Survey is suitable for most conventional buildings and provides a traffic-light rating system covering structural concerns including RAAC. For more complex or older buildings, a RICS Level 3 Survey offers a more detailed inspection with comprehensive analysis of structural integrity, and is specifically recommended where RAAC is known or suspected.
Both surveys will identify problematic materials including RAAC and asbestos, and will cover current structural condition, risk levels, potential remediation requirements and cost implications. Specialist RAAC management services are also available for building owners who need ongoing assessment and risk oversight rather than a one-off inspection.
How much does a RAAC survey cost?
The cost depends on which survey level is appropriate for the building. A Level 2 assessment typically starts from around £400 and a Level 3 from around £650, varying with building size and location. You can get an instant quote from Surveyor Local using our online quote generator.
What this mean for your purchase
Discovering RAAC in a building you are considering does not automatically mean walking away, but it does require careful consideration. You need to understand the current structural safety of the affected areas, the likely cost of remediation, the impact on value and what mortgage lenders and insurers will require before proceeding.
Getting a detailed assessment gives you the information you need to make that decision with confidence, and puts you in a stronger position when negotiating with the seller.
RAAC management and professional assessment services
Surveyor Local works with RICS chartered surveyors across England and Wales. If you are concerned about RAAC or any other structural issue in a property you are considering buying, get a no-obligation quote online or call our friendly team on .