Formerly Faddish, 'Green' Is Standard

by Jennifer Ellis  on Monday, Jul. 23, 2012 12:00 am  

Keith Wingfield, owner of River Rock Builders of Little Rock, said that ensuring that duct work is sealed properly increases an HVAC system's energy efficiency. (Photo by Jason Burt)

Many of the trends in commercial building are making their way to residential building as well. The reason to buy a green home is the same as it is for commercial structures: energy efficiency.

According to a McGraw-Hill Construction study of residential builders, 83 percent said a focus on energy efficiency was what made green homes built today more environmentally friendly than they were two years ago. And green home building has doubled nationwide in just three years from 8 percent in 2008 to 17 percent in 2011.

"There has been a shift away from green for the sake of being green to core principal of energy efficiency," said Keith Wingfield, owner of River Rock Builders in Little Rock.
"People assume from an energy-efficiency standpoint that all new homes are created equal - and nothing could be further from the truth," he said. "My challenge as a builder is to build the most energy-efficient [structures] for the least dollars."

Products alone are not necessarily the answer, he said. However, understanding what they do and not overdoing it can make a difference.

Using a combination of polyurethane spray foam insulation and less costly cellulose insulation is a good example of how to get the most energy efficiency for your money, Wingfield said. Because the polyurethane foam expands and provides a good air seal, using 1 inch of it will work to provide the seal, and to provide the insulating thickness needed he uses the cheaper cellulose.

Keeping insulation at the right depth and ensuring air and moisture barrier joints are taped are low-tech but important practices, Wingfield said. Other methods he employs in the quest for energy efficiency include using infrared cameras to find gaps in insulation and building envelope pressure tests to check for air tightness. Both practices are similar to those offered as part of ongoing energy services for high-tech energy-efficient commercial green buildings.

Wingfield also conducts duct-blast tests to determine the percentage of leakage in a newly installed HVAC system. Some new systems can have 30 percent leakage, which isn't good because the system may never shut off or may require a larger system to compensate for the leaking. There will always be some leakage, he said. But when conducting the duct-blast test, Wingfield said, he looks for less than 10 percent leakage to achieve energy efficiency, though he often can reduce leakage to 5 percent.

Choosing to make $10,000 worth of energy-efficient upgrades can create a high-performance home and the costs will be recouped in energy savings in just a couple of years, he said. 

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