The construction industry faces a tough climate challenge. Construction produces 11 percent of total Dutch CO2 emissions. That has to be drastically reduced, and it is still not succeeding, even by building circularly and biobased. Can it be done better? Yes, argues Fred Feddes on behalf of the Mevrouw Meijer foundation, in this City essay. It can be done by stopping demolition. Preserve and utilize existing buildings, maintain them, renovate them periodically, and they can last indefinitely. Virtually any existing building can be adapted to new use and sustainability requirements, with CO2 emissions far lower than demolition and new construction. Six case studies from housing and school construction show with hard figures how beneficial this is for the climate, and also financially. They come from the many years of research practice of Ms. Meijer and EcoQuaestor. They inspire, ground, and point the way to better practice for anyone involved in construction, from any angle.