The site for the Red Cross Headquarters in Colmenar Viejo, in northern Greater Madrid, is the end of a single family housing development. It offers an strong slope, with great urban visibility and an extraordinary view towards the city of Madrid from the highest level. This situation provides three different street fronts with a clear North-South orientation in its longitudinal axis, so it is convenient to position the building in this direction to respond, besides to the urban context showing its public condition, to the sunlight conditions and towards the far view of the skyline of Madrid. This orientation, besides, permits to take advantage of the slope naturally to organize the building program in two levels and to resolve the car parking under the upper level. Thus the building has two different entries, one for vehicles in the lower level and other for pedestrians in the upper level, where most of the public program takes place. In this way, we avoid the construction of a basement, with the consequent economic savings, at the same time that the building performance enhances, reducing its contact with the ground. The structure is resolved with white concrete walls and slabs, using a polyurethane formliner in the exterior side, forming a vertical pattern that allows the integration of the aluminium profiles for the openings, with the same cross section and rhythm, as a window lattice. The volume works as a continuous structural tube, supported only by two columns, producing large cantilevers. This tube-shape structure, that is also the building enclosure, faces South throughout the terrace that covers the whole front and solves its setback with floor to ceiling woodwork and glass to allow, simultaneously, great views and the needed solar control. The terrace integrated in the building is part of the exterior landscape and offers the possibility for outside activities in continuity with indoor spaces. The open, transparent, free-flowing and continuous nature of the project aims to contribute and to make easier the important work of social integration carried out by the Red Cross.