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New 'green' roof project could change the way homes are built

Wednesday, May 21, 2008

(10/8/07 - KTRK/HOUSTON) -- Scientists say the temperature of Earth could rise by as much as 10 degrees by the end of the century if nothing is done about greenhouse gases. In an effort to combat global warming, some in Houston are making buildings that are environmentally friendly.

Chicago has a city ordinance requiring new high rise construction to include grass roofs. Houston has a few green-roofed commercial buildings, but it also has a university building that may make this viable for our own homes in the future.

In the 1930's, rooftop gardens were part of any penthouse. The old Hogg building in downtown Houston has its manicured mid-rise grounds. More recently, UT's School of Public Nursing added native grasses to what had been an asphalt roof.

Greenhouse gases have already been reduced. Now at the University of Houston central campus, another roof has gone green.

Geoffrey Brune with the U/H Architecture School said, "If all the buildings in Houston had green roofs then the temperature would be very different. … I think it would be significantly noticeable … by several degrees."

Traditional hard surface roofs and concrete reflect heat back into the atmosphere. At the same time, roofing material also absorbs heat, which forces homeowners to use more energy to cool the home itself.

Consider the native grass roof on a reclaimed architecture lab building. It uses a couple of inches of specially engineered soil in a specially designed platform.

"You'll notice the trim piece is perforated to let the drainage through," said U/H Architecture Dean Joe Mashburn.

That controls rain runoff and potential flooding. There are other green roofs around, but this is the only one in the region that is slanted like most residential roofs.

"I think this is a new system, particularly for residential use," said Mashburn. "I think it will become more popular as people realize the enormous cost of utilities."

It's forward looking and it has already cut down on air conditioning costs. The students who work in the building have barely noticed.

"You open the building and turn on the fan and the air gets going and it's cool actually," said architecture student Arvin Abadilla.

The way the roof holds up after several years of use will help decide whether it has a future in subdivision housing. It's unconventional for now in Houston, but one day it may not be.

Brune said, "I can't imagine people wouldn't want flowers on their roofs."

For now the downside is the price. For one side of the slanted building roof, it was $7,000 in additional cost, paid for by grant money. As utility costs increase though along with public acceptance for eco-friendly building, the cost of a green roof will go down.
(Copyright © 2007, KTRK-TV)

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