By Carol Sonenklar
Green Right Now

They said it couldn’t be done: A LEED platinum house for $100 per square foot in hard construction costs.

Builders, architects, real estate developers, among others, have expressed skepticism that green building could be done inexpensively. One persistent notion is that sustainable home building is expensive because of higher upfront costs for cutting edge technology and design. Its become conventional wisdom, in some corners, that green building carries a 10 percent upcharge, at least.

And some believe that aiming for the highest certifications, like the U.S. Green Building Council’s platinum LEED rating, requires even higher costs.

Chad and Courtney Ludeman, and Nic Darling, the owners of Postgreen, set out to prove these assumptions wrong.

The 100K House Project began in 2007, has produced two adjoining row houses. The first one is nearing completion and is on track to become the first LEED platinum-rated residential home in Pennsylvania. The Ludemans will be living there. The second house (nicknamed the 120K house for its slightly higher costs) is under contract. Since breaking ground, the team has received an award from the American Institute of Architects Philadelphia Chapter and is among the finalists for the Pennsylvania Environmental Council’s 2009 Philadelphia Sustainability Award

Chad Ludeman has a background in manufacturing engineering and worked as an efficiency expert for several years; his wife Courtney Ludeman is a real estate broker. Darling, a friend and business associate of the couple, is a writer and marketer. The three of them had rehabbed a few houses several years earlier and wanted to focus on new construction specifically for younger buyers in their neighborhood of New Kensington.

But there was a problem.

“Any new house here is the standard 2000-square-foot, three-bedroom, two-bath type that costs about a half a million,” Darling explains. “We wondered why we were building houses that no one we know can afford to buy.”

The 100K house (and the 120K house) lists for $265,000. It is on an infill lot, which satisfies a key LEED (Leadership in Energy Efficiency and Design) requirement to reuse available land. Ludeman’s house is actually the prototype for a series of proposed LEED-certified houses, all of which are projected to cost between $200,000 to $300,000, with varying floor plans and options.

Did the team meet their $100 per square foot target for construction costs on the prototype? Darling says that their goal of making the 100K mark is well within reach. At a few weeks out from completion, they’re actually under that benchmark for the “hard construction costs” of the 1,100-square-foot space, which includes all the building materials and labor. “Soft costs” for architects and consultants, as well as the cost of the lot, are not included, and were not intended to be part of the building cost benchmark, he said.

So how did they do it?