Frequently Asked Questions
about Green Roofs

Classifications

1.  What is a “green roof”?

What: At its most essential level, a green roof is a roof surface which is designed to accommodate vegetation and/or accommodate human use (ie. specialty gardens, patios, play areas, ponds, driveways, etc.).

Not only is utility of the roof space created but numerous ecological and economic advantages exist. These advantages include: extended roof life expectancy, sound insulation, thermal insulation, additional usable space, natural habitat for flora and fauna, high water retention, climate moderation, pollution reduction, let alone the visual enhancement of the city landscape. (Some of these benefits are detailed in the following FAQ, but all details can be found on the website.)

Where: Generally, modern green roofs started over 30 years ago in Germany and are rapidly becoming a popular building addition in countries around the world.

2. What is an extensive roof versus an intensive roof?

Extensive green roof: A roof which is covered in low growing vegetation and is usually installed to create advantages from the additional surface protection and maximize ecological benefits.

Intensive green roof: A roof which can be covered with large plants, shrubs and trees as well as structures for human activity (walkways, benches, fountains, parking, and so on). They are usually intended to take the form of well-kept gardens. Anything on the ground is possible on the roof given that an adequate load bearing capacity of the building is present.

These definitions are based on the FLL (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau e.V.) Guideline for the Planning, Execution and Upkeep of Green Roof Sites, release 2002.