Tulsa Time: A Green Duplex in Oklahoma Earns LEED Platinum Certification

A deep green duplex makes the most of its urban lot and invites Oklahomans to embrace sustainable building.


| September/October 2010



duplex bathroom

Reclaimed wood countertops bring warmth to the bathroom.

Photography By Michael Shopenn

Rachel and Shelby Navarro shared their home—the first in Oklahoma to achieve the U.S. Green Building Council’s top Platinum certification level—with their community through workshops, open houses and even a ribbon cutting attended by Tulsa’s mayor, a state legislator and the Oklahoma Secretary of the Environment. More than 1,000 people toured the home and learned from manufacturers about its green features, which include a grass roof and artful use of reclaimed wood. Fellow Tulsans had been both curious and enthusiastic, but Rachel hadn’t truly understood how much her home mattered until the day she looked up from her housework and saw a young man and his mother looking in the window.

“I could tell they didn’t want to be too obvious,” she says. “He came to the door, and he said, ‘I am really sorry. We are not trying to intrude, but I wrote a paper on this house in one of my classes.’ He goes to the University of Oklahoma, and one of the projects a professor assigned to his class was to research and write a paper on our house. The whole class.”

Architect and homeowner Shelby Navarro was raised by his grandparents on an organic farm about 20 miles from Tulsa in Verdigris, Oklahoma, in a house heated by the sun. Shelby’s grandfather, who grew up during the Depression, “understood the importance of getting value out of everything and doing the most with the least,” Shelby says. “He would take me on recycling trips. We would collect and sell cans. He made wine glasses out of old beer bottles. It was a way to clean up and reuse things.”

With that upbringing, Shelby knew plenty of tricks to help him achieve a Platinum score when he designed his own home. Leadership in Energy and Environmental Design (LEED) Platinum certification requires at least 90 “green” points (out of 136); the Navarros’ grass-roofed duplex garnered 105.

For the foundation, Shelby added extra fly ash—a waste product from coal-burning power plants—to make the concrete stronger and more durable. “Fly ash concrete tends to be slightly less strong at the usual test time, but after a year of continued reaction with lime in the concrete, it is substantially higher in strength than non-fly ash concrete,” he says. Exterior walls are made of structural insulated panels (SIPs)—recycled wood chips bonded with wood glue and sandwiched around high-density foam. Shelby chose trusses prefabricated out of 2-by-4s instead of traditional 2-by-12s. He describes these smaller pieces as “a little bit easier to come by and a little bit less destructive.” Builders further reduced waste by using leftover wood to block in the wall panels.

The grass roof helps keep down the heat, resulting in less energy use while providing an urban wildlife refuge for birds, butterflies, bugs and spiders. It also filters pollutants out of storm water and protects the underlying roof from UV rays, temperature fluctuations (which cause shrinking and swelling) and hail. Shelby estimates the roof will last three times longer than a standard roof.

bones
9/26/2015 5:13:17 PM

who can assist me in designing such a home in my city ?






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