"A green roof, or rooftop garden, is a vegetative layer grown on a rooftop. Green roofs provide shade and remove heat from the air through evapotranspiration, reducing temperatures of the roof surface and the surrounding air. On hot summer days, the surface temperature of a green roof can be cooler than the air temperature, whereas the surface of a conventional rooftop can be up to 90°F (50°C) warmer."   - EPA


Green roofs significantly reduce heating and cooling costs by better insulating the building.  They also capture rainfall and reduce runoff.  Designs can be as elaborate as a rooftop park with full trees and habitat for wildlife, breaking up the hardscape of urban living.


Green roofs require a substantial amount of maintenance and can be costly to implement correctly.  Because they are installed on flat-roofed buildings, many existing structures could not be retrofitted with a green roof.



Example 1: EPA

EPA Green Roofs Page

Description: EPA webpage for Green Roof information.  Page goes through the benefits and costs and has links for references.


Example 2: Urban Design Tools for Low Impact Development

Urban Design Tools: Green Roofs

Description: An overview of how green roofs work and links to other references


Example 3: Minnesota 

MN PCA Design Criteria for Green Roofs

Description: A step by step guide to the process to designing and installing a green roof.