For the practical user like engineers, inspectors, experts, approval authorities and senior executives of fire departments, this reference book describes requirements to the fire fighting water supply to hydrants which contribute substantially to the improvement of functional security. Structural Engineering and security related requirements to hydrant systems for fire fighting inside a building are presented and contrasted with each other according to international standards and legal requirements. The findings for the technical use are derived from the interdisciplinary research results in cooperation with universities, public authorities, leading fire departments, fire department training centers, professional associations as well as the industry and presented intelligibly. The first part of the research report addresses directly the user. In this section, the different procedures and their assessment methods with summarized measurement results are specified and evaluated. The second part comprises the scientific basic information of the single specialist fields. The respective measurement results and further derivations are illustrated in detail. Through the cooperation of the affected specialist fields, an investigation has been carried out on which specific requirements to fire fighting water supply to hydrants in high-rises and large properties exist in order to provide a yet more secure fire fighting water supply for personal and property protection. It has been identified which limit values for pressure and flow rates on the nozzle are acceptable under security related aspects considering the applied pressure regulation method and which technical requirements have to be taken into account. This reference book will be available as hardcover, PDF, iBook and App in German, English, Spanish and French.