Soak Up the Rain: Green Roofs

Green roofs have a layer of plant material that absorbs water like a sponge. They capture water when it rains, slowly releasing it through evaporation and plant use. Green roofs can significantly reduce the amount of rain water that would otherwise run off an impervious roof surface. Green roofs can also help reduce building energy usage and noise levels while increasing the durability and lifespan of the roof compared to conventional roofs.

Green roofs are being increasingly used in urban areas where space constraints limit the use of other stormwater management practices.

Note: Structures must be able to support the loading of green roof materials under fully saturated conditions.

Information About Green Roofs

Estimating the Environmental Effects of Green Roofs: A Case Study in Kansas City, Missouri, 2018, US EPA (pdf) (3 MB)
The case study lays out a replicable analytical framework for use by decision makers in assessing the multiple benefits of green roofs, including stormwater runoff reductions and public health improvements.

The Benefits and Challenges of Green Roofs on Public and Commercial Buildings, A Report of the United States General Services Administration, 2011 (pdf) (9.5 MB)
This report includes a literature review of 200 research studies, in-depth analysis of green roof benefits, an original cost-benefit analysis, discussion of challenges and best practices, and assessment of further research needs.

GSA Green Roof Tracker

Green Roofs, Technical Preservation Services, National Park Service, US Department of the Interior
Historic buildings are great opportunities for sustainable development and are regularly being rehabilitated to incorporate green design features while still preserving their historic character. One way of increasing the sustainability and energy performance of a building is to install a green roof. Find background for applying green roof technology to historic buildings.

Green Roofs, Green Infrastructure, U.S. EPA

Local resources

• Connecticut
• Maine
• Massachusetts
• New Hampshire
• Rhode Island
• Vermont

Connecticut

Residents Guide to Green Roofs, Connecticut Department of Energy and Environmental Protection (pdf) (534 KB)
Introduces green roofs, including information on the types and benefits, and residential applications.

Connecticut Stormwater Manual, Connecticut Department of Energy and Environmental Protection
Chapter 4 includes information on green roofs (pdf) (2 MB).

Maine

Maine Stormwater Best Management Practices Manual, Maine Department of Environmental Protection
Volume 3, Chapter 10 includes information about green roofs.

Massachusetts

Green Roofs and Stormwater Management, Massachusetts Department of Environmental Protection
Information on green roof benefits and costs.

New Hampshire

Chapter 4, Interception Practices, New Hampshire Stormwater Manual, New Hampshire Department of Environmental Services (pdf) (1 MB)

Rhode Island

Green Roof Projects around Rhode Island, LID Inventory, Rhode Island Stormwater Solutions, Department of Environmental Management

Vermont

Green Roofs, Vermont Department of Environmental Conservation, Watershed Management Division
Basic information about green roofs.

Vermont Low Impact Development Guide for Residential and Small Sites, Vermont Department of Environmental Conservation (pdf) (5 MB)
Includes some basic introductory information about green roofs.