Almost 40% of global CO2 emissions are caused by the construction and building sector. When energy and building materials production are factored in, it accounts for about 28% in Germany. The German government’s goal is to reduce greenhouse gas emissions in the construction and building sector by up to 67% by 2030.Almost 40% of global CO2 emissions are caused by the construction and building sector. When energy and building materials production are factored in, it accounts for about 28% in Germany. The German government’s goal is to reduce greenhouse gas emissions in the construction and building sector by up to 67% by 2030.