I first learned about green roofs, (aka. Living roofs, vegetated roofs) by watching a talk by William McDonough on TED. He planned the development of a city in a lush grassy area in China--and when he showed the pictures of the plan, the city was just as green as the original open field! I’d never seen this kind of design in my area, and since then, I’ve been pleased to see it popping up on green buildings in major cities.
But what about homes? Many of the highly publicized examples we keep seeing are of commercial buildings, but can we do this on our homes? Or, more correctly, is it worthwhile doing it on our homes?
Well, as usual with most green building improvements, the answer seems to be “yes!” So, here’s more on how:
Green roofs are roofs with a top layer of soil, drainage and protection layers, all combined to support growing plants. Underneath this top layer is the standard water-proof roofing membrane found on all roofs. You can have a lighter green roof (called “extensive”) with 6 inches or fewer of soil, or a heavier roof (“intensive”) with more than 6 inches of soil. This second type can support larger plants and a garden-like layout, whereas the lighter type supports small, grass and brush-like vegetation. If you have a sloped roof, the light “extensive” roof is a great option.
Of course (at least to me) the idea of having an entire roof lawn or garden is just awesome by itself. It could be a garden sanctuary to just sit, above and away from the street-level noise and fumes that normal gardens sometimes sit in. But outside of that, there are practical, social and monetary benefits of these green additions.
For your community: Green roofs decrease noise pollution, mitigate heavy rain runoff, and decrease the heat island affect of an urban neighborhood.
For your green conscience: Green roofs provide a habitat for natural wildlife (especially roofs with the native plants), improve air quality, and absorb rain water, which in some cases can be collected for reuse.
For your pocketbook: Green roofs provide excellent insulation, keeping your home cool in the summer and warm in the winter--making for big savings in energy costs. As mentioned above, they also enable rain water harvesting, helping to save the world and water costs. Some green roofs even incorporate solar collectors, saving big on electricity.
More and more contractors and architects are incorporating green roofs into their projects. There are a lot of resources out there for you--learn more, and then get a green professional who can answer your questions. Most of the time, people installing this type of work do an excellent job.
In my book, all this stuff makes green roofing something to consider.