Prioritisation of old apartment buildings for energy-efficient refurbishment based on the effects of building features on energy consumption in South Korea

Since the 1970s the construction of high-rise apartments has been prolific across Asia. More recently, due to changes in legislation, there has been a growing trend towards refurbishment for those old apartments, however this has primarily focused on the economic benefits and rarely taken energy saving and the reduction of carbon emissions into account. Therefore, this study aims to evaluate what features in old apartment buildings need to be taken into account in refurbishment strategies. The method is threefold: evaluating energy consumption in old apartment buildings; identifying effective building features on energy consumption; and ranking the effects of building features on energy consumption. The results show that old apartment buildings have consumed excessive energy for space heating and cooling. Maximum 43.65 kWh/m2/year in space heating and 5.70 kWh/m2/year in cooling were reduced as a result of the transformation of eight building features, accounting for 70.9% of total variance in factor analysis. Three most influential features, which should be used to priorities for refurbishment schemes, have been identified by multiple regression analysis: the conditions of building envelopes, heating methods and the sizes of building units. Therefore, the priority should be given to these three features.