Buildings generate nearly 40% of annual global CO2 emissions. About two-thirds of the global building stock will still exist in 2040 and, if left as they are, these buildings will continue to generate unsustainable levels of carbon emissions.
For existing buildings, mounting evidence is pointing to retrofitting as a realistic solution. When compared to tearing them down and building anew, improving the efficiency of the buildings we have is also a less carbon-intensive alternative.