Around 40% of the world’s CO2 emissions come from the building sector. Köbi Gantenbein is an advocate of renovation. “Every house not built helps the Alpine ecosystem. A quarter of a building’s total CO2 emissions are due to its construction. This so-called grey energy is found, among other things, in the production of concrete and steel, transport and construction. Demolition also generates other emissions. Materials have to be disposed of at great expense.”
