Overheating Risks and Adaptation Strategies of Energy Retrofitted Historic Buildings under the Impact of Climate Change: Case Studies in Alpine Region

Abstract

Energy retrofits can enhance the liveability and efficiency of historic buildings while preserving their historic and aesthetic values. However, measures like improved insulation and airtightness may increase their vulnerability to overheating and climate change may further worsen their performance in the future. This paper investigates indoor overheating risks brought by climate change in retrofitted historic buildings and proposes effective adaptation strategies. Firstly, local weather conditions are analysed to identify homogenous climatic zones. For each climatic zone, “a business-as-usual” emissions scenario is adopted, and most representative regional climate models are selected to obtain hourly output of future climate projection. A comparative study is adopted where typical alpine residential buildings, “Portici house”, are simulated with regard to future energy use and indoor thermal state using the dynamic model in EnergyPlus. Energy use and indoor thermal conditions are compared before and after energy retrofit, as well as under present and future climate conditions. The results demonstrate that retrofit interventions could significantly improve energy efficiency of historic buildings in both present and future scenarios. A change in climate together with retrofit interventions will, however, result in higher risk of indoor overheating in South Tyrol. Potential negative side effects of energy retrofit could be controlled by adopting adequate shading and ventilation approaches that minimise, or eliminate, the risk of overheating during high temperature periods while optimising historic buildings’ energy performance.

A Review on Technical Challenges and Possibilities on Energy Efficient Retrofit Measures in Heritage Buildings

“…Airtightness and improved insulation may result in overheating of buildings which might exacerbate in the future due to climate change [93]. A study in historical buildings in South Tyrol, Italy suggests that due to the combined impact of climate change in future (2021-2050) and energy retrofit, overheating in retrofitted buildings can reach up to 33% (1881 h) [93].…”

“…Airtightness and improved insulation may result in overheating of buildings which might exacerbate in the future due to climate change [93]. A study in historical buildings in South Tyrol, Italy suggests that due to the combined impact of climate change in future (2021-2050) and energy retrofit, overheating in retrofitted buildings can reach up to 33% (1881 h) [93]. Hao et al [93] suggest that overheating can be reduced to a large extent by using wooden window shutters and a ventilation strategy wherein ventilation is active when indoor and outdoor temperature is higher than 24 • C and 18 • C, respectively.…”

“…A study in historical buildings in South Tyrol, Italy suggests that due to the combined impact of climate change in future (2021-2050) and energy retrofit, overheating in retrofitted buildings can reach up to 33% (1881 h) [93]. Hao et al [93] suggest that overheating can be reduced to a large extent by using wooden window shutters and a ventilation strategy wherein ventilation is active when indoor and outdoor temperature is higher than 24 • C and 18 • C, respectively. Incorporating wooden shutters in historical buildings is not an issue in their study region as the authors report that several historical buildings used to have hinged shutters [93].…”

“…Hao et al [93] suggest that overheating can be reduced to a large extent by using wooden window shutters and a ventilation strategy wherein ventilation is active when indoor and outdoor temperature is higher than 24 • C and 18 • C, respectively. Incorporating wooden shutters in historical buildings is not an issue in their study region as the authors report that several historical buildings used to have hinged shutters [93].…”

Adaptive Strategies Used in Urban Houses to Overheating: A Systematic Review

“…Even though, the adaptive strategies were been identified in the existing works (Drury et al, 2021), little attention is paid to the implementation of their application in the planning and designing of buildings in Nigerian urban areas (Hellwig et al, 2019;Alozie et al, 2019;Manzano-Agugliaro et al, 2015). This has been a barrier to effectively managing the effects of overheating in urban houses (Hao et al, 2022). Given the above, this paper aims to investigate available literature on ways to improve the thermal comfort of occupants in urban housing provision by focusing on the effective utilisation of different adaptive strategies adopted for overheating in urban houses with the following objectives: i.…”