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.

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.

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.

You should contact green roof manufacturers directly and speak to a sales representative. Corporate Member websites can be found in our Members section.

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.

Green roofs can facilitate a significant improvement in the LEED^tm 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 LEED^tm credits when used with other sustainable building elements. For example, green roofs can earn direct credits under the following:

• 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 LEED^tm Green Building System, by Richard Kula in The Green Roof Infrastructure Monitor, Spring 2005)

For general information on green roofs, please check out the rest of our website and the Living Architecture Monitor magazine. 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.

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.

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 This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Contact your local or county government for possible incentives.