Green Roofs by Diane deWilde

City Hall, Chicago, IL Ballard Public Library, Ballard, WA roadtrippers.com Definition green roof noun 1. A roof covered with vegetation, designed for its aesthetic value and to optimize energy conservation. Collins English Dictionary – Complete & Unabridged 2012 Digital Edition

Types of Green Roofs

roadtrippers.com Extensive Ballard Public Library, Ballard, WA Intensive City Hall, Chichago, IL

Public Benefits Aesthetic Improvement Waste Diversion Stormwater Management Moderation of Urban Heat Island Effect Improved Air Quality New Amenity Spaces Local Job Creation Benefits Private Benefits Energy Efficiency Increased Roofing Membrane Durability Fire Retardation Reduction of Electromagnetic Radiation Noise Reduction Marketing Design-Specific Benefits Increased Biodiversity Improved Health and Well-Being Urban Agriculture Educational Opportunities photo: blog.parents-choice.org

Benefits Environmental Moderation of Urban Heat Island Effect Energy Efficiency Stormwater Management Improved Air Quality photo: blog.parents-choice.org

Urban Heat Island Effect (UHI) (i.e., Cities are hotter than the surrounding rural areas because of human activity) Day: 1 - 3°C higher Night: up to 12°C higher

photo: biophiliccities.org Plants cool the environment: Transpiration Take in water through roots Release water from leaves Evaporation From plant leaves and soil Plants and UHI

photo: biophiliccities.org Urban Development Reduction in vegetation reduces natural cooling Impervious surfaces absorb and re-emit solar radiation Plants and UHI

photo: biophiliccities.org Plants and UHI Green Roofs Fewer impervious surfaces Reduce ambient temperatures by 30°C (Jaffal et al., 2011)

Reduces energy consumption 23% decrease in heating needs 75% decrease in cooling needs (sempergreen.com) Web.mit.edu

Stormwater Management

Pounds of Pollutants Removed Annually sites.gsu.edu Improves Air Quality

Green Roofs Sequester CO2 Green roofs using sedum sequester 375 g C m -2 (Getter, 2009) Convert all commercial and industrial roofs in Detroit, MI = 55,252 tons of carbon sequestered (Getter, 2009)  Equivalent to “removing more than 10,000 midsized SUV or trucks off the road for a year” (Getter, 2009)

Questions?

Sources: Photos: Title page; City Hall, Chicago, IL; Ballard Library, Ballard, WA; Structure of a Green Roof; Pre-Settlement Conditions, Historic Urban Development, and Urban Greening; factor/ factor/ Graphs and Charts: Types of Green Roofs; Urban Heat Island Effect; washington-d-c-s-urban-heat-island-effect/ washington-d-c-s-urban-heat-island-effect/ Energy Usage Chart; Percentage Water Retention; Pounds of Pollution Removed Annually; Data: Benefits; Installation costs; Environmental advantages green roofs;