In December 2018, the Department for Education (DfE) and the Local Government Association (LGA) made building owners aware of a recent building component failure in a property constructed using RAAC. In May 2019, the Standing Committee on Structural Safety (SCOSS) raised an alert to emphasise the potential risks from such construction, highlighting the failure of a RAAC panel roof construction within an operational school. This collapse was sudden with no apparent warning. Since then, we have been made aware of further sudden collapses of RAAC panels in roofs that appeared to be in good condition. It is therefore essential that all responsible bodies undertake work to identify any RAAC they have in their estate following the stages set out in this guidance.Prior to this, in the 1990s, there had been other concerns raised relating to structural deficiencies in RAAC by both the Building Research Establishment and SCOSS. It was recognised that thein-service performance was poor with cracking, excessive displacements and durability all being raised as concerns.