On April 30th, Toronto will become the first city in North America with a bylaw that requires roofs to be green. And we’re not talking about paint. A green roof, also known as a living roof, uses various hardy plants to create a barrier between the sun’s rays and the tiles or shingles of the roof. The plants love the sun, and the building (and its inhabitants) enjoy more comfortable indoor temperatures as a result.
— Toronto Becomes First City To Mandate Green Roofs, CripsGreen.