Building certification systems have succeeded in making the sustainability of buildings comprehensively assessable. This creates incentives for the construction world and enables building owners to gain control over sustainable construction. Certification proves the quality and sustainability of a building, which offers both ecological and economic benefits. These include lower operating costs through energy savings, greater attractiveness for tenants and buyers and an increase in the value of the property. Building certification systems are important as they make a significant contribution to reducing CO2 emissions and protecting the environment. At the same time, they sensitize building owners, architects and users to sustainable building practices and thus contribute to a more environmentally conscious society.