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Green Roofs: City Dweller's Green Oasis


Did you know what one of the biggest contributors to green house emissions in any building is the roof?  It's true.  According to "The Building Sector: A Hidden Culprit" published on the Architecture 2030 website (© 2006-2009), buildings are responsible for almost half (48%) of all energy consumption and greenhouse gas emissions and consume 76% of all power plant-generated electricity.  Roofs are a big part of this energy usage and output.  If people could somehow stop consuming so much power at home they could make a huge impact on their carbon footprint

For example, traditional roofs have fluctuating tempatures due to sunlight. Some studies have measured a difference of 45°F (25°C) in a single day. The temperature within the building must then be controlled through the use of other equipment, such as furnaces and air conditioners.  Next, these roofs reflect solar heat causing the urban heat island effect, a phenomenon where the temperature in cities is higher than in the surrounding countryside.  Lastly, the buildings destroy the natural vegitation in the area, destroying the ability of CO2 to be collected.

Green roofs may be the answer.  A green roof is a building covering that incorporates vegetation in the engineered design. These roofing systems involve layering specific materials to provide a waterproof seal for the building, drainage, and a growing medium for growing specific plants.  Green roofs not only reduces insulation costs, controls tempature and re-populate the space with plants, but also absorb much of the additional solar energy into CO2 conversion.  An amazing system that is begining to gain usage in many cities.

Their are two problems with the system.  First, the system is expensive.  A green roof costs between $10-$40 per square foot on average.  This is a high up-front costs but the long term savings are immense and outweigh this sum.  The more serious problem is weight.  Many building cannot structurally support the weight of soil and vegetation on their roofs.  In these case other low costs options are available.  For example, you may paint the roof white instead of black to not attract heat and solar rays.  To read more about this topic I suggest Kate Galbraith's article at the New York Times regarding this subject.

Comments

I don't know about you guys

I don't know about you guys but I think green roofs are exquisite and extraordinary beautiful. Just take a closer look at these pictures, I am impressed with all that. I really hope that for the future every block will have one of these, we could all use some more green in our cities.
Garry, Dallas roofer

Thank you Garry

It is always wonderful to hear from people within the industry.  I have seen a number of green roofs here in the SF Bay Area and in my trips to Boston & New York, but I have not been priveleged to visit the great state of Texas.  What is the adoption of roofs like these in Texas, Garry?  I know the biggest problem in California is the heat and drying of plants which create a fire hazard.  Does Dallas also have this problem?

Sean Fitzpatrick is a burgeoning green entrepreneur and journalist with a juris doctor from Santa Clara University, School of Law. Currently, he is business development and community manger of KeenForGreen.com.

What about ivy?

I love the pictures - I always thought these garden roofs were just for city dwellers who want an occasional break from the city life.  I never realized the environmental impact they could have.  Have they come up with any solutions to the weight and cost dilemmas?  Does it help to just grow a bunch of ivy over the roof or does it need to be more complex then that? (or does the ivy still weigh too much?)

Clean Tech Open

Actually, one former competitor in the clean tech open will be featured here who provides a solution to your questions.  Stay tuned.

Sean Fitzpatrick is a burgeoning green entrepreneur and journalist with a juris doctor from Santa Clara University, School of Law. Currently, he is business development and community manger of KeenForGreen.com.

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