Key drivers of life-cycle carbon emission for residential buildings in cold zone of China: A comparative study of thermal design and morphological design factors

Abstract

Reducing life-cycle carbon emissions (LCCE) from residential buildings is essential for achieving carbon neutrality in the building sector. LCCE arises from operational and embodied carbon emissions, influenced by both thermal design and morphological design factors. It is essential to clarify the key drivers of LCCE to develop effective carbon reduction design strategies. However, previous research often studies these factors in isolation, neglecting their interactions, which limits the promotion of zero-carbon residential building design. This study proposed a research framework to address these limitations based on architectural typology and orthogonal experiment method, which integrates thermal design and morphological design factors. This framework was applied to analyze the key drivers of LCCE for residential buildings in Xi'an, a typical cold zone city in China. 4533 high-quality information data on existing residential buildings were collected. By adopting architectural typology, more than 1500 typologies were obtained. K-means clustering was used to refine and obtain 78 prototype buildings. A series of simulations were conducted using the orthogonal experiment method to identify the key factors covering both thermal and morphological aspects. The results showed that plane form (PF), exterior wall K-value (WK), and transparent envelope K-value (TK) are the key drivers, while transparent envelope solar heat gain coefficient (SHGC) and building orientation (BO) were influencing factors. The above five factors can collectively explain 95 % of the variation in LCCE. Moreover, based on factor importance level and the factor value's carbon reduction contribution, the low-carbon design strategies for residential buildings in cold zone of China were proposed.