Predominantly used from the 1950s to the 1990s RAAC was considered a cost-effective alternative to traditional concrete, offering faster production and easier installation. However, despite its initial appeal, Reinforced Autoclaved Aerated Concrete (RAAC) exhibits lower durability compared to conventional concrete, typically lasting around 30 years. What makes RAAC particularly worrisome is its susceptibility to structural failure when exposed to moisture due to its porous nature, which permits water infiltration and can lead to the corrosion and weakening of any reinforcing bar (rebar) within the material.

The dangers of RAAC have brought to light not only structural vulnerabilities but also the potential revival of asbestos-related risk due to asbestos use crossing over with the same period of time during RAAC use. Before Phase 1 RAAC Assessments can be conducted, an asbestos pre-refurbishment survey must be conducted.