Brad Hardin, a 27-year-old Kansas City architect, used to be a bit sheepish about combing the Internet for reusable building materials.

“If you’re looking on eBay and your boss walks by,” Hardin said, “he might wonder, ‘Is he buying an Xbox or a reused door?’ ”

Hardin — a huge advocate for green building practices — decided there had to be a better way to locate used building materials such as bricks, wood, steel and, yes, even doors. So he teamed up with contractor Nathan Benjamin and Web designer Dan Fox to create planetreuse.com, a Web site that connects people in the construction industry looking to acquire — or sell — reusable materials.

The result? Builders get used materials at a lower cost, and — since fewer new materials are needed — less of the planet’s energy and resources are consumed.

Planetreuse.com is contributing to the greening of Greensburg, Kan., a small town virtually demolished by a tornado a year ago. Hardin is working with Kansas City’s BNIM Architects to attain used materials for several building projects in Greensburg, including a new school and city hall.

One idea is to use materials from the soon-to-be deconstructed Menninger Clinic in Topeka to build the 120,000-square-foot Greensburg school, slotted to be the first Leadership in Energy and Environmental Design Platinum school in Kansas. LEED Platinum is the highest-possible green rating from the U.S. Green Building Council.

Joe Keal, an architect at BNIM working on the Greensburg school, said he’s looking at salvaging bricks, wood, lockers and bathroom mirrors from the Menninger Clinic.

A big part of Hardin’s job is educating clients on why reusing materials is a smart decision all around.

“Older buildings, especially the ones that are over 100 years old, the beams are actually fantastic. They’re just as strong as the day they were put in,” Hardin said.

“And a lot of people think going green costs a lot more,” he said. “You’ve got a lot of material out there that’s unique in character, but that now would cost a small fortune.”

Take granite, for example: Planetreuse.com recently acquired a large amount of the pricey rock from a demolished Southern Illinois University building. Now, Hardin just has to figure out where that granite’s going.“Putting it in its second life is kind of cool,” he said.

That’s one batch of granite that won’t have to be dug from the earth, transported, polished and so on.

“If you get right down to it,” Hardin said, “material reuse is the greenest way to do it.”