A study on the moisture risk assessment path for exterior wall of existing residential building in Shanghai based on hygrothermal simulation analysis

In the context of global climate change, retrofitting existing buildings to enhance their resilience has emerged as a pressing necessity. In China, high-rise residential buildings constructed before 2000, predominantly situated in densely populated urban areas, have become focal points for urban retrofitting initiatives. These buildings, often fully occupied and representing the oldest and most valuable structures, face intricate retrofitting challenges due to flawed original designs, non-standard construction practices, and inappropriate historical retrofit decisions. This study investigates the exterior wall of Wuding Building in Shanghai as a case study, employing WUFI Pro software to dynamically model and analyze the coupled heat and moisture transport processes under localized conditions. The primary high moisture risks are identified, and hygrothermal fluctuations and condensation risks are compared across various architectural scenarios. This study integrates specialized and localized hygrothermal-related inspections into the large-scale urban health inspection project in China's super first-tier city central areas, addressing the gap in existing building envelopes durability assessment. It aims to establish a universal workflow for wall hygrothermal assessment and lay the groundwork for standardized durability evaluation in China. Recognizing the absence of a universal hygrothermal critical threshold, this study addresses the localization of databases, and integrates them into assessment process. Using a typical residential building as a pilot, it develops a fundamental assessment process before large-scale retrofitting projects, identifying key links and tools.