Identifying practical sustainable retrofit measures for existing high-rise residential buildings in various climate zones through an integrated energy-cost model

Sustainable building retrofit can provide a great opportunity to reduce the energy consumption of existing buildings to commensurate the climate policies and enhance the building energy performance. Given it strategic importance, there is no shortage of research studies on sustainable building retrofit globally in particular the retrofit measures and technologies for different types of buildings. Despite that, sustainable building retrofit is climate and location specific, and decision-makers are still facing challenges to identify an optimum set of retrofit measures for different climatic conditions according to the trade-off between energy saving and retrofit cost. One reason for that is because of the lack of available information especially those related to the cost of sustainable building retrofit measures. This study aims to develop an integrated energy-cost model for selecting the optimal retrofit solutions for existing high-rise residential buildings in various climatic zones in China. Based on in-depth literature review and analysis of published reports, different alternative retrofit measures for wall, window, shading system, heating and cooling systems, and renewable energy technologies for buildings in different climate zones of China are identified. The retrofit costs related to the identified sustainable building retrofit measures are analyzed by referring to the local renovation techniques and cost in each zone through developing a set of equations. A total 28 practical sustainable building retrofit measures along with a set of retrofit options are identified. A deterministic decision framework is developed to facilitate decision-makers achieving a specific energy saving target and evaluating the associated costs based on the identified retrofit measures for high-rise residential buildings in the studied climatic zones. The practical implications of the deterministic decision framework are examined through the prototype buildings in climatic zones being studies. The findings not only actively support the selection of cost-effective sustainable retrofit measures for high-rise residential buildings in China, but the methodological framework and its implications are also equally applicable to other countries with diverse climatic characteristics and standards of living.