Why build a green roof? As the industry becomes more globally aware of environmental impacts within building structure, which is inevitable for a growing population, green roofs are a wonderful solution to help mitigate these issues.
Although there are several benefits, it’s important to assess the site and its conditions before building one. Apart from providing natural beauty, green roofs can be installed easily with the right products and have instantly matured mats of sedums and native grasses from trusted growers that specialize in the plant palette used with these systems. A green roof is a layered system with key components to ensure its success.

Andrea Cochran Landscape Architects, a timeless and immersive firm, designed a green roof as a part of a two-building multi-family project in San Francisco, California. The site, formerly an asphalt parking lot, allows for a public cooridor, creative seating, lighting, and a native plant palette that has since become a vertebrae within the spine of the city. Located on Broadway St, this project allows for 178 permanently affordable homes in the heart of the city along the historic waterfront district. Naturally, the community was concerned about a flat white roof obstructing the views and aesthetics of the district. San Francisco has the Better Roofs Ordinance, passed in 2017, delegating that 15-30% of newly constructed roof space be allocated to solar and/or green roofs. Seeing this as an opportunity, ACLA partnered with Live Roof, a green roof specialist, to enhance the quality of life for the residents and to foster life with biodiversity through native and drought-tolerant plantings. Green roofs can cool a single-story building by 50 percent and can capture rainwater that can be reused with underground cisterns, like this design, to save the owner costs on energy and irrigation. This project has helped to set the precedence of future green roof projects.

To bake the perfect green roof cake, follow this recipe:

Waterproofing of the roof deck

Root Barrier + Protection Fleece

Drainage Membrane

Filter Layer + Geotextile Filter

Green Roof Substrate + Growing Medium

Vegetation

Sources:https://www.sfchronicle.com/sf/article/Goodbye-Embarcadero-Freeway-Hello-affordable-16586640.php