We can summarize the search for efficiency in building in several steps: the first of these is good orientation and location, followed by a suitable outer skin. Then there is the use of efficient facilities and finally the use of renewable energy. It is vital that due consideration is given to each of these steps to create an efficient final product. In this sense, Savener has prepared many projects that use renewable energy, above all for the purpose of heating. The peculiar nature of this project lies in the vertical and horizontal operation of the field of collectors (to favour integration) using a single accumulation tank and without disrupting its stratification despite the different operating temperature ranges in the collector field.