저탄소 녹색성장
Green Roofs for Healthy Cities in www.greenroofs.org
keesan
2008. 10. 16. 07:40
About Green Roofs
A green roof system is an extension of the existing roof which involves a high quality water proofing and root repellant system, a drainage system, filter cloth, a lightweight growing medium and plants.
Green roof systems may be modular, with drainage layers, filter cloth, growing media and plants already prepared in movable, interlocking grids, or, each component of the system may be installed separately.Green roof development involves the creation of "contained" green space on top of a human-made structure. This green space could be below, at or above grade, but in all cases the plants are not planted in the "ground'. Green roofs can provide a wide range of public and private benefits.
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In North America, the benefits of green roof technologies are poorly understood and the market remains immature, despite the efforts of several industry leaders. In Europe however, these technologies have become very well established. This has been the direct result of government legislative and financial support, at both the state and municipal level. Such support recognizes the many tangible and intangible public benefits of green roofs. This support has led to the creation of a vibrant, multi-million dollar market for green roof products and services in Germany, France, Austria and Switzerland among others. In Germany for instance, the industry made 700 million DM in sales in 1997, up from 500 million DM in sales in 1994. The industry continues to experience growth with with 13.5 million square metres of green roofs constructed in 2001, up from 9 million square metres built in 1994.
Green roof technologies not only provide the owners of buildings with a proven return on investment, but also represent opportunities for significant social, economic and environmental benefits, particularly in cities. Find out more about the private and public benefits of green roof technologies below.
Frequently Asked Questions about Green Roofs
Why a green roof?
There are generic private benefits for virtually all projects, benefits, specific to the design and type of green roof, and benefits/incentives related to public policy, which have proven to be critical to developing the market in Europe:
Private BenefitsPlease Note: while there are similarities among green roofs, each installation is unique. Hence, all technical performance details provided will vary by region, climate, building and green roof type and design. These figures are provided as generic examples only and should not be used for designing projects without expert advice and opinion.The following benefits can be achieved with virtually all green roof infrastructure systems. Economic Benefits - cost savings opportunities for the building owner include:
Sound Insulation
The following benefits may be achieved, depending on the type and design of the green roof system (i.e., accessible/inaccessible, intensive/extensive, integrated with other building systems or not). Economic Benefits
Amenity Space and Aesthetics
Food Production
![]() Herb Garden on Vancouver's Fairmount Waterfront Hotel (courtesy David Walker)The following benefits may be achieved, depending on the type of public policy support for green roof installations in your area.
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Public BenefitsPlease note: All technical details provided will vary by region, building type and materials used. These figures are provided as generic examples only and should not be used for projects without expert advice and opinion. Economic - Improved Air Quality - Temperature Regulation - Water - Social - Preservation of Habitat & Biodiversity - Local Food Production Public policies that support green roof installations will create jobs for the following:
Although no exact figures exist, it is estimated that the roofing industry in Germany employs approximately 12,000 people, and if all flat roofs were to be greened, this figure would increase to approximately 100, 000. Community cost savings opportunities include:
Filtration of Airborne Particulates:
Carbon Dioxide/Oxygen Exchange:
Temperature Regulation Moderation of the Urban Heat Island Effect:
The arrows in this diagram illustrate the nature of how green roofs reduce the urban heat island and improve air quality. For more information, see the Spring 2001 issue of the Green Roof Infrastructure Monitor.
![]() ![]() ![]() The above images demonstrate the effect of a green roof on local heating - note the difference in energy radiated via evaporation-cooling vs. latent heat between the two scenarios. (Used by permission of author: Marco Schmidt) Building Insulation:
Industrial Cooling:
Creation of Microclimates:
Water Stormwater Retention:
Water Filtration:
Temporal Delay of Stormwater Runoff and Reduced Runoff Volume:
Source: National Research Council's Institute for Research in Construction ![]() The graph above records the cumulative rainfall and runoff from the Green Roof and the Reference Roof during a 34mm (1.3 inches) rain event over a 15h period in October 2001. The green roof delayed runoff and reduced the runoff rate and volume. For more details on this research conducted by the National Research Council's Institute for Research in Construction, see the article on page 7 of the Fall 2002 issue of the Green Roof Infrastructure Monitor. Aesthetics:
Health & Horticultural Therapy:
![]() A green roof by Garland on a nursing home
Improved Safety:
Recreation: ![]() Corporate Golf Course Green Roof Community Building: Preservation of Habitat & Biodiversity Habitat: Flora & Fauna: Local Food Production Green roofs can provide new opportunities for urban agriculture. There are many benefits to growing and distributing food locally including:
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What do I need to know about my building before I initiate a green roof installation?
You will need to know the slope, the structural loading capacity, and existing materials of the roof, as well as the nature of any drainage systems, waterproofing, and electrical and water supply in place. You should also consider who would have access to it, who will do maintenance, and what kind of sun and wind exposure the roof gets.
For a deeper insight into green roofs and green roofs design, look for one of our Green Roof Design 101 - Introductory Courses in a city near you.
For a deeper insight into green roofs and green roofs design, look for one of our Green Roof Design 101 - Introductory Courses in a city near you.
What kinds of landscape design should I use and what plants can I grow on my roof?
Plant selection depends on a variety of factors, including climate, type and depth of growing medium, loading capacity, height and slope of the roof, maintenance expectations, and the presence or absence of an irrigation system. A landscape architect would be able to advise you on suitable plants and design of the plantings. See the landscape contacts below.
How much does a green roof cost?
The cost of a green roof varies considerably depending on the type and factors such as the depth of growing medium, selected plants, size of installation, use of irrigation, and whether they are to be accessible on inaccessible - intensive, semi-extensive or extensive. Intensive green roofs typically require greater investment but confer the benefits of accessibility. An installed extensive green roof with root repellant/waterproof membranes may be installed for $10-$24 US per square foot. While green roofs typically require a greater initial investment, it is important to keep in mind that they can extend the life of the roof membrane and reduce the heating and cooling costs of your building. Speak to a qualified green roof professional about the range of costs and benefits for different green roof systems and designs. Search green roof professionals in our online member database.
How can I purchase a green roof system for my home or building?
You should contact green roof manufacturers directly and speak to a sales representative. Corporate Member websites can be found in our Members section.
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Green Roof System Hamilton Building in Portland, OR |
Green Roof System Mountain Equipment Co-op in Toronto, on |
Modular Green Roof System Low lying shrubs |
Who can design and install a green roof?
Landscape architects and contractors frequently design green roofs and can install the living components (i.e., growing medium and plants).
Because green roof systems include materials not found on conventional roofs, we recommend that you choose a qualified roofing contractor with experience in green roof installation to install the non-living components (e.g., vapour barrier, waterproof membrane). Contractors can be found in our Corporate Members section.
You can also contact a roofing consultant, who will assess your roofing design needs, ensure quality control and recommend a suitable green roof system.
How many LEEDtm credits can I recieve?
Green roofs can facilitate a significant improvement in the LEEDtm rating of a building, contributing as many as 15 credits under the system, depending on design and level of integration with other building systems. In some instances, while green roofs may not contribute directly to achieving points under the system, they contribute to earning LEEDtm credits when used with other sustainable building elements. For example, green roofs can earn direct credits under the following:
(the above is an excerpt from Green Roofs and Maximizing Credits under the LEEDtm Green Building System, by Richard Kula in The Green Roof Infrastructure Monitor, Spring 2005)
- Reduced Site Disturbance, Protect or Restore Open Space
- Landscape Design That Reduces Urban Heat Islands, Roof
- Storm Water Management
- Water Efficient Landscaping
- Innovative Wastewater Technologies
- Innovation in Design
(the above is an excerpt from Green Roofs and Maximizing Credits under the LEEDtm Green Building System, by Richard Kula in The Green Roof Infrastructure Monitor, Spring 2005)
Where can I learn more about green roofs?
For general information on green roofs, please check out the rest of our website and The Green Roof Infrastructure Monitor. More information can also be found on some of Our Members websites.
For a deeper insight into green roofs and green roofs design, look for one of our Green Roof Design 101 - Introductory Courses in a city near you.
What sort of research is being done on green roofs?
A considerable amount of research on the public and private benefits of green roof infrastructure in different climate zones, different built environments, and at different scales needs to be conducted in order to forge a new industry through the development of supportive public policy.
One of Green Roofs for Healthy Cities important goals is to encourage that research through activities like the GRHC Research Committee.
What sort of Policy and Funding support is available for green roofs?
Green Roofs for Healthy Cities is working with local partners in a number of cities to develop cost effective direct and indirect financial support for green roof implementation that meets local/regional needs.
One of the ways that we try to encourage the development of local markets for Green Building is by running Green Roof Symposia in various cities. For more information on this initiative, please contact
Jennifer Sprout .