Although solar thermal systems are technologically mature and cost effective, they have not yet been sufficiently used in building design, where they should be playing a greater role in the reduction of fossil-fuel consumption. One main hindrance to adoption is the generally low architectural design quality of the building integration of these thermal systems. As confirmed by the application of photovoltaic elements in buildings, improving the architectural quality of building integrated system leads to the adoption of a given solar technology even more than price reduction or technical advances. And in the case of solar thermal collectors, which for technical reasons have to be mounted very close to the point of consumption, the architectural integration issue becomes determining. Starting from a definition of architectural integration quality and related criteria, this book will help both architects and manufacturers improve their design work. Architects will find recommendations to optimize the integration quality, thus making the best out of the generally limited flexibility and low formal quality of presently available collectors; and examples of inspiring integration and innovative products are presented. For manufacturers, the book will provides a set of guidelines for the development of new multifunctional and flexible products conceived from the outset for building integration, thus improving the market offer.