In this book, leading experts from academia and practice describe design and optimization methods for the generation of efficient shell forms and topologies. Some of these techniques are part of the long history of the theory of shells, others have been developed or first used in practice by the authors themselves. Recent years have seen a renaissance of shells. Through advances in computational techniques and power, as well as novel fabrication and construction methods, engineers and architects have been imagining and creating elegant thin-shell structures. For shells to be efficient, their shape should depend on the flow of forces and vice versa and therefore their design requires a process of form finding. The ‘ideal’ form of a shell may need to fulfil additional architectural, mechanical or technical aspects necessitating some form of optimization. This makes the design and engineering of shell structures a highly involved process.