The European Technical Specification CEN/TS 19101:2022, "Design of Fibre-Polymer Composite Structures", constitutes a milestone for the use of fibre-polymer composites in civil engineering works. This book comprises around 400 background reports covering the most relevant paragraphs of the Technical Specification. It provides supplementary information to the Technical Specification, justifies the options that were followed and introduces references that were considered. Among other aspects, this makes it possible to assess the basis of design, the values adopted for partial factors, conversion factors and creep coefficients, provisions for structural analysis, resistance models for structural members, connections and joints, and provisions for durability and detailing. The book also identifies research needs in this field to increase knowledge of the behaviour of fibre-polymer composite structures and for possible future development of the Technical Specification towards a Eurocode standard. The only guide to practical fibre-polymer structural design in accordance with the principles and terminology of the structural Eurocodes, this book is ideal for professional engineers working in structural design, as well as a source of consensus information for graduate students and researchers in the area.