Feasibility analysis of retrofitting existing residential towards the EnerPHit standard in HSCW zone: A case study in Guilin, China

Abstract

In response to the increasing demand for thermal comfort and the rising trend of building energy consumption in the hot summer and cold winter (HSCW) zone of China, there is an urgent need to implement higher standards of energy retrofit programs for existing residentials. Practical strategies and technical solutions still need to be improved in China. The Passive House standard (and its EnerPHit standard) aims to achieve ultra-low operational energy consumption through passive strategies. However, studies and examples of passive houses and low-energy buildings are rare in hot climates, especially in the HSCW zone of China. This paper presents the representative of the existing residential in Guilin, China. Simulation modeling through DesignBuilder and a sensitivity analysis were performed to conclude that airtightness, envelope, glazing type, and roof are the most critical factors affecting the energy consumption of the building. Furthermore, the combined solution was validated by optimizing the different retrofit parameters, resulting in a model that meets the energy objectives. The feasibility of the combined solution was also analyzed from the energy, economic, and thermal comfort points of view. Ultimately, the optimal solution that meets the objectives is obtained through a multi-criteria decision making (MCDM) approach for a more sustainable building. The methodology and results of this study provide an effective decision-making process for designing and evaluating energy retrofits for typical residential buildings in the HSCW zone, as well as a rigorous basis for policymakers to update the design codes for retrofitting buildings in HSCW zone.