Analysis of the additional energy-saving potential of residential buildings after mandatory zero-energy buildings to achieve carbon neutrality in South Korea

Led by the European Union (EU), several countries have announced carbon-neutral goals and introduced related legislations. For example, the Korean government has recently announced a roadmap for the introduction of mandatory zero-energy buildings (ZEBs), because the building sector is a major contributor to carbon emissions. To evaluate the feasibility of achieving carbon neutrality through the legislation of mandatory ZEBs, we analyzed the energy-saving potential of residential buildings and determined whether ZEB standards could be strengthened further. The energy consumption of residential apartments was calculated, and the possibility of additional energy savings beyond those dictated by ZEB certification standards was evaluated by assessing the energy performance of individual element technologies. It was observed that, to achieve carbon neutrality, there were limits to regulating individual element technologies alone, and a comprehensive approach was required. In addition, after the introduction of mandatory ZEBs, the degree to which the hot water and plug loads are affected by user behavior increases; therefore, it is also necessary to design a policy to encourage users to exhibit energy-saving behavior. This study can be used as a reference for the design of building energy policies after the introduction of mandatory ZEBs. •Residential energy use under the mandatory zero-energy building policy is assessed.•More energy savings are possible by strengthening zero-energy building standards.•Domestic hot water and plug load use needs to be reduced in zero-energy buildings.•Energy-saving actions by the occupants are required for carbon neutrality.