Decision-making framework for enhanced thermal resilience of façade-retrofits

Abstract

Climate extremes are becoming increasingly frequent and intense worldwide, with greater pressure on ecosystems, the built environment, and humankind. Heat waves, in particular, are overheating indoor spaces and thermal comfort as one of the major comfort requirements of buildings is disrupted or, in the most extreme situations, lost. In extreme cases, this can lead to life-threatening circumstances and explains the high morbidity and mortality during past heat wave events. It is crucial to urgently develop a more climate-resilient built environment, that can effectively respond to the future climate hazard of heat waves. Hereby, the building envelope has a key role to mitigate the impact of the exterior environment on the occupants’ indoor comfort. Accordingly, exploring possibilities of façade design for “future-proof” buildings is important to reduce health risks and improve the daily quality of life. However, the lack of comprehensive research on assessment methods for evaluating the influence of façade design on building thermal resilience proves the current challenges of implementing the concept of “resilience” in a practical manner.
This research aims to improve the design process of retrofit options, increasing thermal indoor comfort during heat waves, and enhancing long-term building thermal resilience. It includes the development of resilience indices, based on the assessing different stages of thermal resilience during extreme heat periods. By conducting a systematic literature review focusing on thermal resilience terminology and corresponding assessment methods, the study identifies limitations and gaps in current research. A novel method is proposed, which incorporates future climate scenarios and multiple resilience indicators. While most existing research solely relies on the measurement of a single indicator to measure thermal resilience, this thesis demonstrates the importance of combining multiple resilience indicators to comprehensively assess the influence of façades on building thermal resilience. The proposed framework aims to be universally applicable and adjustable, while assessing the short- and long-term impacts of retrofit interventions on the performance of the façade. The resulting index visualizes how various façade retrofit variables can influence thermal resilience at the building level, which provides a deeper understanding of dependencies and thus enhances improved decision-making during the development of façade retrofits.