The terms 'green roof' and 'roof garden' are often used interchangeably, but there is a subtle distinction:
Green Roof: Primarily designed for environmental benefits, such as stormwater management, energy efficiency, and improved air quality. May have limited access and be primarily for aesthetic purposes.
Roof Garden: Primarily designed for recreational use, featuring walkways, seating areas, and a wider variety of plants. Requires more structural support and maintenance.
Essentially, a roof garden is a type of green roof designed for active use, while a green roof may or may not be accessible for recreation.