{"682782":{"#nid":"682782","#data":{"type":"news","title":"Can Cool Roofs Help Atlanta Beat the Heat? Georgia Tech Experts Weigh In","body":[{"value":"\u003Cp\u003EIn a unanimous vote on June 2, the Atlanta City Council approved a significant ordinance requiring all new and replacement roofs to be built with light-colored, reflective materials, commonly known as \u201ccool roofs.\u201d The ordinance, set to take effect in one year, is part of a growing effort to reduce the city\u2019s vulnerability to extreme heat.\u003C\/p\u003E\u003Cp\u003EGeorgia Tech researchers say the new policy marks a major step forward in climate adaptation, especially for heat-vulnerable communities, and could help position Atlanta as a national leader in urban resilience.\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EHow Cool Roofs Can Help Hotlanta\u0026nbsp;\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003E\u201dOn any given summer afternoon, temperatures in Atlanta\u2019s intown neighborhoods can be as much as 15 degrees Fahrenheit higher than in the city\u2019s most forested areas,\u201d said\u0026nbsp;\u003Ca href=\u0022https:\/\/planning.gatech.edu\/people\/brian-stone\u0022\u003EBrian Stone\u003C\/a\u003E, professor in the School of City and Regional Planning and associate director of Georgia Tech\u2019s Center for Urban Resilience and Analytics.\u003C\/p\u003E\u003Cp\u003EThat spike is partly due to the urban heat island effect \u2014 a phenomenon driven by heat-trapping materials like concrete, asphalt, and dark rooftops, combined with the loss of trees and natural landscapes. The impacts are not just uncomfortable \u2014 they\u2019re dangerous. Extreme heat is now one of the deadliest forms of weather in the U.S., with disproportionate effects on low-income communities, elderly residents, and those without access to air conditioning.\u003C\/p\u003E\u003Cp\u003EAccording to\u0026nbsp;\u003Ca href=\u0022https:\/\/arch.gatech.edu\/people\/patrick-kastner\u0022\u003EPatrick Kastner\u003C\/a\u003E, assistant professor in the School of Architecture, rooftops are key contributors. \u201cA major driver [of heat buildup] is dark, heat-absorbing material that stores solar energy during the day and then re-radiates it at night. If you look at a satellite image, for most of the day rooftops have more exposure to the sun than building facades \u2014 so the material choice there matters a lot.\u201d\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EThe Power of Reflective Roofs \u2014 and Trees\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EStone and his students conducted modeling that found that widespread adoption of cool roofs across Atlanta could lower summer afternoon temperatures by more than 2 degrees Fahrenheit in many neighborhoods. That\u2019s comparable to findings in other global cities like London, where cool roofs have reduced average temperatures by up to 2 degrees Celsius (3.6 F).\u003C\/p\u003E\u003Cp\u003EBut cool roofs are only one part of a broader urban cooling strategy. In the same study, Stone\u2019s team showed that planting trees in just half of Atlanta\u2019s available planting zones could yield an even more dramatic effect, reducing temperatures by 4 F or more in some areas.\u003C\/p\u003E\u003Cp\u003E\u201cCool roofs are highly effective, but pairing them with increased urban tree cover would multiply the benefits, especially for neighborhoods currently lacking shade,\u201d Stone said.\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EEquity and Energy Impacts\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EAtlanta\u2019s ordinance requires cool roofing materials on new commercial construction and when existing commercial roofs are replaced. While that may sound like a technical design tweak, Stone emphasized its equity implications.\u003C\/p\u003E\u003Cp\u003E\u201c\u003Ca href=\u0022https:\/\/urbanclimate.gatech.edu\/urban-heat-risk-and-health\/\u0022\u003EResidents in South and West Atlanta\u003C\/a\u003E, where tree canopy is sparse, and energy costs take up a larger share of household income, stand to gain the most,\u201d Stone said. \u201cWhen a cool roof is installed as part of a required roof replacement, those households will see meaningful reductions in cooling costs month after month.\u201d\u003C\/p\u003E\u003Cp\u003EKastner added that cool roofs could ease pressure on the electrical grid, lowering peak energy demand required for cooling during extreme heat and possibly reduce the risk of outages.\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EDurability, Maintenance, and Design Trade-offs\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EStone noted that cool roofs tend to extend the life of roofing materials by limiting thermal degradation. However, he and Kastner also flagged some trade-offs.\u003C\/p\u003E\u003Cp\u003EFor example, highly reflective coatings can create glare, especially on sloped roofs near neighboring buildings. The ordinance accounts for this by setting different standards for flat and pitched roofs. Maintenance is another consideration: over time, reflective coatings may degrade or become dirty, requiring periodic cleaning to maintain performance.\u003C\/p\u003E\u003Cp\u003E\u201cAesthetics and material compatibility may also challenge adoption when it comes to historic buildings or for roofs already outfitted with solar panels,\u201d Kastner said. \u201cBut advancements in roofing technology, including high-performance materials that aren\u2019t\u0026nbsp;plain white, offer more flexible options than ever before.\u201d\u003C\/p\u003E\u003Ch4\u003E\u003Cstrong\u003EA Cool Roof Policy With National Impact\u003C\/strong\u003E\u003C\/h4\u003E\u003Cp\u003EWhile cities like New York and Chicago have implemented cool roof programs for over a decade, Atlanta\u2019s proposed ordinance is one of the most comprehensive in the country \u2014 applying to all roof types, not just flat industrial ones.\u003C\/p\u003E\u003Cp\u003E\u201cAtlanta is steadily emerging as one of the most climate-resilient cities in the U.S.,\u201d said Stone, pointing to the city\u2019s urban forest and growing network of floodable parks as complementary resilience strategies. \u201cAdding a best-in-class cool roofing ordinance to that portfolio is a bold step forward.\u201d\u003C\/p\u003E\u003Cp\u003EAnd it could spark innovation across the region.\u003C\/p\u003E\u003Cp\u003E\u201cGeorgia Tech is uniquely positioned to help advance climate-resilient design,\u201d Kastner said. \u201cFrom research on advanced coatings to urban planning tools that target the most heat-vulnerable areas, we\u2019re bringing science and policy together to shape cooler, healthier cities.\u201d\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EIn a unanimous vote on June 2, 2025, the Atlanta City Council approved a new ordinance requiring all new and replacement roofs to use light-colored, reflective materials known as \u201ccool roofs.\u201d Backed by Georgia Tech research, the policy is designed to reduce urban heat, lower energy costs, and improve climate resilience\u2014especially in heat-vulnerable communities. As one of the most ambitious cool roof mandates in the nation, Atlanta\u2019s move positions the city as a leader in urban climate adaptation and a model for other U.S. cities facing rising temperatures.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"City\u2019s New Rule Could Shape Broader Change to Protect Heat-Vulnerable Cities"}],"uid":"35798","created_gmt":"2025-06-13 00:00:16","changed_gmt":"2025-10-24 14:21:32","author":"Ayana Isles","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2025-06-12T00:00:00-04:00","iso_date":"2025-06-12T00:00:00-04:00","tz":"America\/New_York"},"extras":[],"hg_media":{"677228":{"id":"677228","type":"image","title":"Roof installation","body":null,"created":"1749773178","gmt_created":"2025-06-13 00:06:18","changed":"1749773178","gmt_changed":"2025-06-13 00:06:18","alt":"Carpenters build a roof on a residential house","file":{"fid":"261109","name":"AdobeStock_600909189.jpeg","image_path":"\/sites\/default\/files\/2025\/06\/12\/AdobeStock_600909189.jpeg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/06\/12\/AdobeStock_600909189.jpeg","mime":"image\/jpeg","size":3640582,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/06\/12\/AdobeStock_600909189.jpeg?itok=NYDpb4Ix"}}},"media_ids":["677228"],"related_links":[{"url":"https:\/\/resilience.research.gatech.edu","title":"Center for Urban Resilience and Analytics"}],"groups":[{"id":"1214","name":"News Room"},{"id":"1188","name":"Research Horizons"}],"categories":[{"id":"137","name":"Architecture"},{"id":"142","name":"City Planning, Transportation, and Urban Growth"}],"keywords":[{"id":"188349","name":"urban heat"},{"id":"86431","name":"cool roofs"},{"id":"194567","name":"Atlanta ordnance"},{"id":"187915","name":"go-researchnews"}],"core_research_areas":[{"id":"39531","name":"Energy and Sustainable Infrastructure"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003E\u003Ca href=\u0022mailto:aisles3@gatech.edu\u0022\u003EAyana Isles\u003C\/a\u003E\u003Cbr\u003ESenior Media Relations Representative\u0026nbsp;\u003Cbr\u003EInstitute Communications\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}