Underground garages and parking structures are not typical high-rise buildings, but rather sophisticated engineering structures that require specialized knowledge from those involved in planning, execution, and supervision. Parking decks must fulfill both load-bearing and waterproofing functions to ensure long-term usability and durability while preventing construction defects. The reinforcement must be permanently protected from chloride exposure. Water should not become a problem for parked cars and parking facility users. A coordinated interplay among the various specialists is essential, with agreed specifications for the concrete, for crack-width limiting reinforcement, and for a concrete cover of the reinforcement adapted to the construction task. Additionally, detailed designs for joints, slopes, and drainage, combined with additional protective measures, as well as a maintenance and upkeep plan during use, are necessary. This book is aimed particularly at planners in architecture and engineering firms, but also at contractors in construction companies. The content of the book includes guidelines and recommendations on the aforementioned points. In this third edition of the book, the content has been restructured and organized. The revised texts incorporate the statements and specifications of the new and currently valid regulations in an understandable manner. Furthermore, the technical book has been supplemented with a chapter on "Underground Garages," which includes construction principles for water-impermeable structures. Calculation examples for usability assessments regarding early and late restraint, as well as for estimating crack risk and crack safety, expand the scope of the book.