This paper describes the design development of the roof structure for the new Centre Pompidou - Metz. The roof comprises a geometrically complex doubly-curved three-way timber gridshell type structure, the geometry of which was developed using computational form-finding techniques. This paper presents the development of the roof geometry and the structural systems from competition through to tender. The structural analysis and design process is presented, and a summary of some of the developments during construction are also discussed. Ben Lewis, BEng (Hons), CEng, MIStructE Associate, Arup