It is a building of 1004 m2 that has been renovated with sustainability criteria. CO2 emissions in the construction phase were calculated through the ecômetro LCA® tool and a minimisation strategy was contemplated. The final carbon footprint has been of 124tn CO2 (124KgCO2/m2), a fairly small figure given the surface of the building. In addition, the building does not emit CO2 in its use and has offset its carbon footprint, during the construction phase, through a reforestation program in Nicaragua. The air conditioning system is evaporative, more environmentally friendly than traditional refrigeration systems, which use chlorofluorocarbon gases (CFCs). The power supply is 100% renewable..