What are Garden Roofs?
One of the most interesting roof types being proposed and installed as a solution to mitigating the Urban Heat Island phenomenon is the Garden Roof - a better descriptor than the broader term Green Roof that can refer to reflective cool roofs as well. Essentially, the low-slope roof area is covered with a roofing membrane. Installed on top of that roof membrane is a series of planting containers that are filled with growing medium and plants.
Types of garden roofs
Intensive - planned and designed roofs incorporating planting medium up to several feet in depth requiring extensive maintenance. These roofs are intended for public access and use and are usually built-in-place.
Extensive - planting media is eight inches or less in depth with few maintenance requirements and not intended for public access; usually composed of recycled plastic modular planting units.
Benefits of garden roofs
- Mitigate Urban Heat Island effect - saves energy and reduces rooftop temperatures
- Manages storm water runoff
- Aesthetic improvement - adds value
- Reduces glare to surrounding buildings
- Increases oxygen production
- Plants absorb CO2
- Absorbs sound - due to increased mass
- Reduced HVAC requirements