In Praise of Green Roofs

I was walking along the Mississippi River near the post office yesterday and was assaulted by a strong petroleum stench for half a mile.  It was an otherwise crystal clear morning with flawless air quality.  They must have been tarring the roof of the post office building.

Odor and air quality are yet more good reasons to install a green roof rather than using stinky and messy tar.

Meanwhile, the Target Center is getting ready to show off their new vegetated roof championed by Minneapolis Councilperson, Lisa Goodman.  It will be the second largest green roof installation in the country.  The Ford Dearborn Truck Assembly Plant in Dearborn, Michigan trumps the size of the Target at 10.4 acres.  

If this conjures up images of Heidi and goats, you are living in the last century!  New green roofs are constructed from a thin growing medium that is rolled out much like a carpet.  It contains seeds and plants that can survive on a hot dry surface and yet suck up rainwater and act like extra insulation.  This is high tech -- no mowing needed.  

The benefits of green roofs are cool (get it?) :  
1)    Reduction in “heat island effect” on hot summer days from converting a tarred surface into a planted surface.
2)    The planted surface can act as insulation reducing cooling costs in the summer and heating costs in the winter.
3)    The green roof absorbs storm water and helps to insure that little ends up in the Mississippi river.  
4)    Plants help filter pollution out of the air.
5)    It also extends the life of the roof to two times the length of a tar roof.


I am proud of our city staff and council for supporting and following through on this earth-friendly project.  If there is a downside, cost can still be a barrier for would-be copycat building owners.   Even so, I have a fantasy that someday I will be able to look down from an airplane and see mostly green on our downtown roofs.   The Target Center is a good move in that direction!  Kudos to Lisa and all who made it happen!  We need to celebrate...