Green Roofs CDAE 170

1. Green RoofsCDAE 170 By: Holly Crimmins, Teddy Dobbin & Justin Geibel

2. What are they? • Green Roofs or “eco-roofs” are roofs planted with vegetation or soil that grow on the actual roof. • A green roof can also be a roof that encompasses solar panels • They are not roofs made with green shingles

3. How do they work? • Most use a specially formulated lightweight compost or soil as a growing medium • Depth of soil or growing medium ranges from 6 inches on extensive green roofs to 4 feet on intensive green roofs • Provide aesthetic value to buildings and a green space for people to enjoy • Vegetation and soil effectively collect rainwater • Green Roofs protect rubber roof membranes from water and sun damage

4. Extensive Designed to be lightweight, maximize the environmental benefits Soil or growing medium is usually 6 inches deep or less, generally planted with native species Usually not accessible to the public Intensive Generally designed as public “green space” for building tenants or general public Heavier than extensive roofs because they require more soil Can support wider variety of plant life, but require more maintenance (irrigation control, soil quality, etc.) Different Types of Green Roofs

5. What plants are typically grown on green roofs? • Plants must be tougher and less nutrient-dependent than most garden plants • The most successful green roof plants are low-growing, shallow-rooted perennial plants that are heat, cold, sun, wind, drought, salt, insect, and disease tolerant • Annuals and Perennials are most often utilized in the landscape design of green roofs • The types of plants chosen depend significantly on regional weather patterns, soil depth and quality, landscape design, roof size, and irrigation systems Example of a useful perennial – Petrorhagia Commonly used annual - Phacelia campanularia Perennial - Campanula rotundifolia

6. What do they do? Advantages • Clean the air by absorbing greenhouse gases like carbon dioxide • Provide space for the plant & wildlife habitat that has been displaced by building • Decrease the temperature on a roof • In a city this can reduce the “urban heat-island effect” • Decrease heating and cooling loads on a roof and the building. More energy efficient building. • Manage and utilize stormwater, and filter toxins and pollutants out of water • Utilize recycled materials that would otherwise be put in landfills

7. Some disadvantages • The cost of replacing the roof with a green roof on it can be expensive • Faulty waterproofing can cause extensive roof damage. • A green roof can place a heavy load on a structure

8. History of Green Roofs • Date back thousands of years. • 500 B.C there were green roofs in the Hanging Gardens of Babylon • Germany has been building modern green roofs for over 30 years • Germany provides indirect and direct subsidies and ordinances for the installation of green roofs • Reduction of storm water taxes • mitigation for the provision of open space • Direct monetary subsidy to developers who use green roofs • Canada is working on a Green Roof Initiative to hopefully provide compensation/initiatives of some sort • New York City, Atlanta, Chicago, Portland OR, Seattle, and Washington, D.C., are looking into different types of incentive programs.

9. Green Roofs at UVM • University Heights North Complex • Davis Center –on the 2nd level of the west side

10. Sources • http://www.hrt.msu.edu/faculty/Rowe/Green_roof.htm • http://www.deq.state.mi.us/documents/deq-ess-p2-p2week-greenroofresources.doc • http://www.garlandco.com/green-roof-history.html • http://www.greenroofs.com/Greenroofs101/industry_support.htm • http://www.burlingtonfreepress.com/apps/pbcs.dll/article?AID=/20070826/NEWS01/708260306/1009 • http://media.www.vermontcynic.com/media/storage/paper308/news/2006/01/31/News/University.Heights.Completed-1545711.shtml • http://www.mngreenroofs.org/types