(A09) Adaptation Strategies for Urban Heat Islands and Multifamily Buildings During Extreme Heat Events

Extreme heat events are becoming more frequent and more severe, increasing the occurrence of heat-related illness and death. Much of this risk is attributed to overheating in multifamily dwellings, particularly in neighborhoods with abundant asphalt, few trees, and limited financial resources. Prior to personally experiencing multi-day extreme heat events, many discount the dangers and the adverse impacts on health, public safety, and infrastructure. This session covers the peer-reviewed research incorporating the extreme heat data recorded from the June 2021 Pacific Northwest heatwave, investigating the extent to which passive cooling strategies and natural cooling could diminish the hours in which indoor heat index levels exceed ‘caution’, ‘extreme caution’, ‘danger’, or ‘extreme danger’ thresholds in the cities of Eugene and Portland, OR, Spokane and Seattle, WA, and Vancouver, BC. Without these strategies interior temperatures can exceed 125 degrees. The same research methodology was used to analyze the September 2022 California heat wave on apartments units in San Francisco. Looking beyond temperatures inside of buildings, urban areas experience higher temperatures than surrounding rural areas, with measured surface temperatures up to 180 degrees and neighborhoods with air temperatures over 15 degrees warmer than others nearby. The District of Columbia released their comprehensive heat plan, Keep Cool DC: Extreme Heat Adaptation Strategy in September 2022, building on their 2016 climate preparedness plan, Climate Ready DC. The plan combines heat adaptation strategies that mitigate urban heat island effects with strategies that aim to keep people safe during high heat events. It considers a range of social determinants on heat risks including housing, pre-existing health conditions, and other sociodemographic factors. Examples from the implementation phase will cover how to increase affordable housing density without increasing urban heat islands and which resilient site strategies result in offering the most cooling for outdoor thermal comfort in the built environment.