Facing the arcaded gallery at Nuevos Ministerios on Paseo de la Castellana in Madrid, the firms totem arquitectos and BETA.Ø have together come up with an efficient alternative to the conventional office building. The faceted volume has been expressly designed to minimize its form factor and facilitate passive ventilation, and incorporates an air conditioning system that operates by means of geothermics, in addition to a double enclosure of glass that makes it possible to combine a kaleidoscopic appearance with an optimal response to solar radiation.