Paper Conference

2020 Building Performance Analysis Conference and SimBuild co-organized by ASHRAE and IBPSA-USA



Ted Kesik, William O'brien, Aylin Ozkan

Abstract: Thermal resilience of buildings is commonly assessed using two metrics: thermal autonomy (TA) is a measure of the fraction of time during a year that a building can passively maintain comfort conditions without active system energy inputs; and passive habitability (PH) is a measure of the duration of time that an indoor space remains habitable following a prolonged power outage over an extended period of extreme weather. An emerging body of research has identified these two metrics as significant indicators of energy efficient building performance. However, there remains a need to achieve consensus about how to coherently model these metrics during the early stages of design to better inform decision making. This paper proposes a framework to establish a common set of conventions, protocols and benchmarks for TA and PH metrics. First, it attempts to address the comfort and habitability indoor temperature thresholds that presently vary considerably in the literature and then to define both comfort thresholds appropriate for the analysis of passive measures in naturally ventilated buildings, and habitability thresholds under extreme conditions of high temperatures and humidity. Second, a consistent methodology for compiling weather data that reflect the impacts of climate change on extreme weather events is advanced. Third, modeling assumptions address the most vulnerable occupants in terms of their age and state of health, but also reconcile, in the case of multi-unit residential housing, the correlation between individual suite behaviour and whole-building performance so that the 'weakest links in the chain' deliver acceptable levels of thermal resilience. This paper also advocates for the inclusion of minimum levels of thermal resilience in future codes and standards to futureproof buildings.
Pages: 61 - 68