Greenroofs

You're probably thinking, what the heck is a green roof? Is it a roof painted green? Or a roof with solar panels? Or is it a futuristic roof that has mechanical arms and reaches into the building to sort the recycling? I'll give you a hint. It's none of those, although I bet I'm not the only one who would prefer to have a machine recycle for me.

A green roof is, in simplest terms, a vegetated roof cover. Instead of shingles or tiles, a green roof incorporates plants and other growing material. There are two types of green roofs: extensive or intensive. Extensive green roofs (aka eco-roofs or low-profile) do not have as many layers as intensive roofs. So they're lighter, cheaper and require very little maintenance. The purpose of extensive green roofs is to build an ecological roof cover with limited human access. Intensive green roofs (aka high-profile) can include a wider variety of plants since the layers are deeper. Intensive green roofs can become full-fledged gardens. Green roofs are often a mixture of both extensive and intensive varieties.

All green roofs vary depending on the structure of the building and the green roof type, but most include a single to multi-ply waterproofing layer, drainage, and plant material, covering the entire roof deck surface.

Green roofs promote energy efficiency, moderate roof temperature, and provide shade in hot weather and insulation in colder months, leading to a reduction in greenhouse gases in the atmosphere. They also help prevent flooding, as the vegetation soaks up excess water, giving our drainage systems a break.

Chicago has over 200 green roofs, covering 2.5 million square feet, more than any other city in the United States. So the real question here is when will Northwestern join in on the green roof fun?

For more information go to http://www.greenroofs.com/index.html, or http://www.explorechicago.org/city/en/about_the_city/green_chicago/Green_Roofs_.html, or http://www.greenroofs.org/grtok/sbp_browse.php, or http://www.inhabitat.com/2006/08/01/chicago-green-roof-program/