The Best Solution for Renovation in Terms of Climate and Economy

EU aims to reach carbon neutrality by 2050. Besides energy consumption reduction, also greenhouse gas emissions have to be cut starting from the production of materials and construction work through the use phase to the end of the use of the building. Existing buildings are estimated to provide a high potential for reducing global warming. This paper focuses on research question, how reasonable are energy efficiencyEnergy efficiency improvements of existing buildings, as the materials used in the process produce CO2 emissions and increase costs compared with conventional maintenance. This issue is a part of the Sustainable DevelopmentSustainable development Goal 13 Climate Action, which integrates climate change measures into national policies, strategies, and planning and a part of Goal 11 Sustainable cities and communities, which tries to increase the number of cities and human settlements adopting and implementing integrated policies and plans towards inclusion resource efficiency mitigation and adaption to climate change. The carbon footprintCarbon footprints of an existing renovated building constitutes mainly from energy consumption emissions. In life cycle costsLife cycle costs, the deciding factor is investment. If the building was heated by zero-emission ground source heat, structural renovationsRenovations would not be worth doing. On the other hand, structural improvement of energy efficiencyEnergy efficiency is recommendable if a building is connected to district heating (DH). Strong reasons, either endogenous or exogenous, must exist for replacing an existing building with a new one. They cannot be justified with the carbon footprintCarbon footprints or life cycle costsLife cycle costs. These results apply to countries, where the energy efficiencyEnergy efficiency of existing buildings is reasonably good.