Green roofs: natural insulation springs up again

The roof above your head might be getting greener, and it won’t be water damage. Well, hopefully.

“Green roofs” can be applied to houses or commercial buildings by designing or retrofitting a roof to accommodate a waterproof membrane, followed by soil or other growing medium and topped off with vegetation. In some cases, the roof might even include an irrigation system. The vegetation can be anything from grass or other ground cover, shrubs and even trees.

And it’s no marginal trend.

Toronto has developed a green roof policy and Vancouver is the home of British Columbia Institute of Technology’s Centre for the Advancement of Green Roof Technology.

Many organizations “cultivating” an interest in the concept list advantages including improved air quality, lower heating and cooling costs and noise level reduction due the insulating value of the substrate, aesthetics and herb and vegetable gardens. Thankfully, no grazing cows have prompted any complaints.

It’s worth nothing that the concept isn’t entirely new. The green roof was probably planted in Canada by Thorfinn Karlsefni and his Viking friends when they settled Vinland in 1010. Viking buildings can still be seen at the L’Anse aux Meadows historic site in Newfoundland.

Later, prairie settlers often built and lived in sod houses during their first few years of homesteading. The prairie grass covering the roof may have made for good insulation but wasn’t always waterproof. Some “soddies” even had green walls, and perhaps this is the next idea to bear fruit — simply coat the sides of buildings with growing media and layer on the seeds for the ultimate extension of the Chia pet.

After all, why shouldn’t the walls match the roof?