All the water collected on the great roof, as well as the water gathered in the square, is channeled to a reservoir located below the circular square. The transparent roofs of the indoor swimming pool and gym are fitted with photovoltaic collector panels, for accumulating electric energy, and thermal collectors, for heating sanitary hot water, which, together, help cover a great part of the energy necessities of this main upper block. A radiant ceiling system, for heating the interior air, helps melt the snow on the roof, avoiding excessive accumulation. Located in the service block, D, next to the service entrance, are the hot water production generators, using natural gas or a tank to be located on the site.