Translating thermal performance into thermal resilience: a simulation framework to assess buildings and communities

Amanda Fraga Krelling
Roberto Lamberts

Building design and operation is undergoing a mentality shift driven by the increasing materialization of long-known threats from climate change. In this context, optimization of performance and cost gives space to also consider resilience. This work aims to propose a simulation framework to quantify and improve the thermal resilience of buildings and communities against overheating threats. Such an analysis is based on resilience profiles that combine a set of six integrated key performance indicators that allow a multidimensional understanding of whether buildings are able to provide comfortable and healthy indoor thermal environments for occupants. An aggregation approach is also proposed to better evaluate resilience at the community scale, leveraging the identification of thermally vulnerable populations. The application of the framework is demonstrated through two case studies, one adopting representative single-family residential buildings exposed to three different Brazilian climates, and another composed of 92 real buildings in the city of Florianopolis, Brazil. The latter also explores the effect of nine weather scenarios on thermal resilience, considering historical (2010s), mid-term future (2050s), and long-term future (2090s) typical meteorological years, as well as years with heat waves within each period. A combination of strategies is considered to improve resilience, such as cool walls and roofs, and solar shading. These analyses were structured within the scope of three journal articles that define the main steps necessary to develop this thesis: (1) quantifying thermal resilience; (2) proposing an evaluation framework; and (3) applying the framework. Results reflect the necessity of planning for resilience. This is because, often, strategies and technologies recommended under current weather conditions might not be ideal in the future. Therefore, a flexible design should be prioritized. Energy consumption for cooling could increase by 48% by the 2050s if not improved current building practices, while excessive overheating issues could reach 37% of the investigated 92 buildings. Simple passive strategies are able to significantly suppress part of this heat stress, especially improving thermal autonomy and energy use. The impact of weather scenarios might be perceived differently depending on the indicator. Thus, a comprehensive thermal resilience analysis should ultimately be accompanied by a thorough reflection on the objectives of quantifying resilience, available resources, planning horizon, and risks assumed for not being resilient.

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