A clearer look at LEED
How glass and glazing earn points in the government’s green building certification program
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The growing popularity of the Leadership in Energy and Environmental Design program of the U.S. Green Building Council of Washington, D.C., means architects will want more natural daylight; that means more glass, said Henry Taylor, architectural team manager, Kawneer Co. of Norcross, Ga., March 5 at the Building Envelope Contractors Conference in Las Vegas.
“Getting light into buildings has to come through our industry,” Taylor said. “LEED is a good opportunity for you and I to sell more glass and aluminum.”
The LEED program offers varying credits for the categories: sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, and innovation and design process. For the latest version of the program, click here.
The program offers several opportunities for points to be earned within glass and glazing; the largest credit opportunity comes in the energy and atmosphere category, where projects can earn up to 10 points for optimizing energy performance.
Low-emissivity glass would earn points in this category. Low-e helps achieve balance between visible light and solar heat gain, reducing a building’s reliance on its heating, ventilating, and air conditioning system, and saving on artificial lighting costs, said James Bogdan, manager of the sustainable design division for PPG Industries of Pittsburgh, during the conference.
“The potential in a low-e building on a yearly basis can be $41,000,” Bogdan said. “Over 25 years, you’re looking at saving over $1 million.”
The industry offers other products to gain points in the category, Taylor said. “We have products that can improve energy efficiency very quickly,” he said. “Sunshades … light shelves inside, overhead glazing, photovoltaics, sloped glazing.”
Changes to a curtain-wall system also can earn credit, when thermal breaks or triple-glazed systems are used. “Simple changes to a curtain wall will have incremental costs—5 [percent] to 8 percent more—but the payback to the project is huge,” Taylor said.
Within the materials and resources category, projects can earn points for recycled content. For glazing, curtain wall suppliers can use aluminum billet with higher-than-normal levels of reused product. “Standard billet has about 25 percent recycled content,” Taylor said. “You can get it higher, but it costs more and takes time.”
LEED awards points to projects that use regional materials, cutting down on transportation costs, said James Bechen, safety and environmental corporate director for Oldcastle Glass in Plano, Texas, during the March 8 Flat Glass Logistics Council meeting in Pittsburgh.
LEED version 2.1 allows projects to earn points if materials are fabricated within a 500 mile radius. LEED 2.2 goes one step farther, requiring materials to be mined or extracted within the 500 mile radius or a project site.
“Where the glass comes from, and where the sand pit is, in comparison with the job site is going to become even more important with the LEED initiative,” Bechen said.
Within the indoor environmental category, glass and glazing can earn points in increasing building ventilation.
-By Katy Devlin, e-Newsletter Editor, e-glass weekly