A modular green roof system costs between $10 and $30 per square foot, as compared to a built-in green roof, which averages between $20 and $35 per square foot.

You may be wondering: are green roofs worth it? Build your own residential green roof system today to turn your roof into a canopy of lovely plants that will keep your house comfortable year-round.

A green roof atop a substation in Tseung Kwan O. Photo: K. Y. Cheng. How a trend to put vegetation on Hong Kong’s roofs ended in a tangled mess. There have been many studies around the world, ...