July 29, 2019August 9, 2019 by landscape-water-conservation

Types of Green Roofs

Two basic types of green roofs are commonly constructed; extensive and intensive.

I. Extensive Green Roofs

PROS

Uses shallow soil medium making it lighter weight
Harsh conditions favor drought tolerant plants such as sedums
Minimal maintenance
Relatively low cost
Pre-planted modules are available for ease of installation

CONS

May require occasional maintenance such as weeding
May require additional irrigation during extended dry periods

low growing plants growing on a rooftop — Example of a simple extensive green roof Photo credit: International Sustainable Solutions Flickr CC BY-NC 2.0

II. Intensive Green Roofs

PROS

Uses deeper soil medium
Can support trees
Can use a large variety of plant types
High wildlife habitat value

CONS

Stronger roof structure is needed to support the weight so may not be appropriate for older buildings
Tend to be more expensive
Similar landscape maintenance to ground level landscapes
May require additional irrigation

Trees and shrubs growing on roof top terraces of the LDS Assembly Hall and Conference Center in Salt Lake City, Utah — Trees and shrubs growing on roof top terraces of the LDS Assembly Hall and Conference Center in Salt Lake City, Utah Photo credit: Abel Cheung Flickr CC BY-SA 2.0

Additional Resources:

An Introduction to Green Infrastructure Practices
Green Roofs as Water-Wise Landscapes

West

Low Impact Development in Northern Nevada Green Roofs

Southeast

Florida: Green Roofs / Eco-roofs
Mississippi: Green Roofs for Southern Landscapes