In July 1992 a colloquium was held at Pembroke College, Cambridge, to discuss the development and performance of tensioned fabric and airsupported structures. Participants included representatives from users and fabricators, as well as engineers and other specialists. The aim of the colloquium was primarily to review the performance of these structures, to understand where the shortcomings were, and to see how the reliability could be improved. The discussion did indicate that air-supported structures could be safe and reliable, but that there were many deficiencies in design, construction, and operation, which resulted in an unacceptably large number of failures. The same did not apply to tensioned fabric structures, which have a good record of reliability. The meeting to be held at the Institution on 2 September 1993 will address these problems and review whether the situation can be improved.