I thought talking a little about the history of green roofs would be a good place to begin now that I've told you about my 'history'- my green roof journey. It turns out that green roofs are definitely not a new phenomenon. There is historical reference to green roofs way back to 600 BC, where stone temples called 'ziggurats' were planted with vegetation. The most notable examples of these temples are the Hanging Gardens of Babylon, located in what is now modern-day Iraq. Around 800-1000 AD, sod roofs were being built in the North Atlantic using grass and seaweed. This architectural style was developed mainly out of necessity - due to a lack of resources, people had to make do with local materials such as mud, sod, reeds, seaweed and stone. Families would line their walls and roofs as a method of protection from cold, harsh winds and rains. You can still see some examples of these houses in Nova Scotia and Newfoundland. The same sorts of materials were used in warmer climates for exactly the opposite reason: to keep buildings cool and protect people from the heat of the sun.

Back to this century - Germany was first to recognize and begin officially studying the benefits of green roof technology. Terraced green roofs (like stairs) were developed in the 1960s. In the 1970s during the oil crisis, West Germany began exploring lightweight adaptations of sod roofs due to a growing concern for the environment and an interest in energy conservation. By the 1980s, German green roof markets had begun growing at a remarkable pace. In 1989, 1 million square meters of roofs had been greened, and by 1996, this number was up to 10 million square meters. It is estimated that 15% of all flat roofs had been greened by 2003. Government incentives, regulations and legislation helped to stimulate this development, and continues to do so. Other European countries began to catch on, adopting roof greening bylaws and planning regulations. Now green roofs are a common feature in the construction industry, becoming popular all over the world!

I truly believe that the green roof industry in North America should be seeing some significant growth over the next few years, as we are already seeing bylaws and incentives put in place in Toronto and Chicago. In Toronto, the bylaw states that a green roof is required on new buildings with a Gross Floor Area of 2000 square meters or more. In a place like Toronto that seems to have less and less green space every day, this makes perfect sense. I can be a little more excited for the future!