Image from Google Earth
Ontario Completes Ottawa Courthouse Green Roof (2012)
"A new green roof at the Ottawa Courthouse will reduce energy costs, improve air quality and help Ontario meet its long-term energy conservation goals. (The roof's green space is bigger than four hockey rinks put together, or one football field.)
The Ottawa Courthouse's green roof is a living landscape that supports 60 varieties of plants and protects the building's structure from the elements. There are 26 separate green roofs spanning multiple elevations, for a total of 70,000 square feet of green space that will help keep Ottawa's air clean.
While a conventional roof lasts only 20 to 25 years, green roofs last at least twice as long. The new green roof will save $23,000 a year in energy costs by reducing summer cooling and winter heat loss by 26 per cent."
I found this after reading about Ottawa investing in solar energy on their municipal buildings:
Ottawa gets green with solar energy project (Metro News, September 2016)
"Eight municipal buildings now equipped with solar panels."