All Posts Tagged With: "greenroofs"

We have long espoused the power of visuals to convey a new idea. Truly, a picture is worth 1000 words. But, it goes deeper than that. Art speaks the language of our heart and enlists our emotions in imagining a different reality. In that spirit, the very talented Gordon Griffin, a sometimes contributor to GOforChange, created this wonderful video called, “What would it look like?” Enjoy! And let us know what you think in the comment section.

[youtube]http://www.youtube.com/watch?v=H5ecxp7Jahw[/youtube]

I’m consulting on a community poolhouse project and the design team is considering a 6,000 square-foot greenroof. The building committee has gotten nervous about this kookie technology: is this decision going to be cursed by future generations? Turns out, there are at least 10 acres of greenroofs in the D.C. area alone. People have figured them out and are installing greenroofs to slow down and filter stormwater, provide a cooling effect and supply a green habitat, among many other benefits . I spoke with two leading experts in our area: John Shepley from Emory Knoll Farms and Rick Truett from Furbish Company . Here are the myths and their answers:

Myth #1. They are expensive and need specialized maintenance.

Yes, they are expensive; they can run roughly double the cost — or more — of a conventional commercial roof. But they also protect the roof’s membrane from the damaging effects of the sun’s UV rays , wind, and extremes of temperature fluctuations. This can double the life of the membrane — or more. Rockefeller Center in NYC has greenroofs from the 1930s that are still on the original membranes. Another important consideration on cost results from systems thinking . That is, for sites that have challenges handling rainwater (aka, stormwater) in conventional ways, greenroofs are a godsend. (See Myth #4 below for more on this.)

Upkeep is minimal. A 10,000 SF mature roof would require 1 to 2 person-days per year, maximum. For the first two years, there would be a bit more maintenance to get it to maturity, but not that much more. On a little roof of less than 2,000 SF, the initial work would be would be 3 days the 1st and 2nd years, then a half-day or less every year after that.

Myth #2. In Europe where they are more common, greenroofs are on buildings with trained, equipped, full-time maintenance staffs. They have to rake leaves in the fall, remove pollen-related detritus in the spring, pick up dead branches throughout the year, reseed or replant bare spots, and fertilize wearing safety harnesses when near the roof’s edge.

I have done tiny, 300 square-foot additions with greenroofs. Continued