This is a comprehensive guide to autoclaved aerated concrete (AAC) for designers, specifiers, users and manufacturers. It provides a model code of practice for the structural use of AAC and provides designers with a complete guide to the structural use of AAC in structural applications in building. The second part contains the complete suite of RILEM Recommendations for specification and testing of AAC. Recommendations for further research, structural design examples and a glossary of terms are also included.