Green Roofs CDAE 170 By: Holly Crimmins, Teddy Dobbin & Justin Geibel

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

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

Different Types of Green Roofs 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.)

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 Commonly used annual - Phacelia campanularia Example of a useful perennial – Petrorhagia Perennial - Campanula rotundifolia

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

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

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.

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

Sources   greenroofresources.doc greenroofresources.doc greenroofresources.doc    D=/ /NEWS01/ / D=/ /NEWS01/ / D=/ /NEWS01/ /1009   media. ws/2006/01/31/News/University.Heights.Completed shtml media. ws/2006/01/31/News/University.Heights.Completed shtml  