Green Roof Types

General Definitions

• Intensive Green Roof System: Green roof site with growing medium greater than 6 inch depth
• Extensive Green Roof Systems: Green roof sites with growing medium less than 6 inch depth
  • Multi-course extensive system: extensive green roof system using two or more distinct types of media, one of which is optimized for drainage.
  • Multi-layer extensive system: single medium extensive green roof system with a high-efficiency synthetic drainage layer instead of a separate drainage course.
  • Single-layer extensive system: single medium extensive green roof system without a high-efficiency drainage layer.
  • Drainage course: aggregate material used for drainage course in a multi-course extensive green roof system.