The book presents new technologies for easy and economical construction of light concrete structures saving materials and CO2. The new super-light technology allows a designer to place forces, where it is optimal, and save material everywhere else. The book also supports this “Direct Engineering” principle with a number of new details and structural principles. The new pearl-chain technology makes it possible to design optimal shapes such as arches, vaults, cupolas, floating tunnels, and shells etc. from inexpensive, and mass-produced components. The new super-light deck-elements presented in the book are now produced in six factories in Denmark, Finland, and USA, and the number is increasing. The book will be of interest for all structural engineers, who would like to save materials, CO2 and optimize their structures, for students learning about the new technologies, and for contractors and architects, who want to investigate new building technologies.