It's over budget, Paul Pedini says of his Big Dig house, but at least "it doesn't leak."

Pedini wants the home — built using steel and concrete salvaged from Boston's $14.6 billion highway construction project — to be a prototype for recycling.

"These materials are as good as you can get," said Pedini, a 51-year-old civil engineer who spent a decade working on the Big Dig. "We were being paid money to junk this stuff. There's something inherently illogical about it."

So instead of dumping top-shelf materials, recycle them into a public housing project, municipal parking garage, prison, even as a replacement bridge.

The key, Pedini said, comes in identifying the second use, so the materials can be engineered for two uses.

It took just three days to erect the frame of the "Big Dig house," a 4,300-square foot home, which cost $645,000 to build. It overlooks a neighborhood of modern homes atop a hill in Lexington, a tony suburb about 12 miles west of Boston.

Pedini worked 11 years on the Big Dig, better known for its failures — water leaks, cost overruns and a recent accident where ceiling panels fell, killing a passenger in a car — than its success in burying the hulking Central Artery beneath downtown Boston. At the time, he was a vice president for Modern Continental Co., one of the project's main contractors.

To keep motorists moving in and out of the city during the oft-delayed project, temporary ramps were built using hundreds of prefabricated concrete slabs.

Architect John Hong, who Pedini hired in 2003 to design his home, was skeptical until he saw the dismantled highway pieces and thought, "It's actually very efficient."

The home was designed by Hong and partner Jinhee Park, founders of Single Speed Design in Cambridge. Concrete slabs, each about 40 feet long and weighing up to 25 tons, comprise the floors and roof. Besides the 600,000 pounds of steel and concrete, the rest of the home has new materials.

Pedini got the materials for free, estimating the giveaway saved Modern $20,000 in demolition and dumping fees.

"People get resentful. They say, 'Well, how come you got the materials?'," said Pedini, who paid a crew $10,000 to transport the slabs on trailers. "Well, to be truthful they belonged to the company. They were trash, they were junk."

The house, built on land that Pedini bought for $410,000, consists of two main living spaces. Up a few steps from the front door is a 1,000-square foot combined kitchen and dining room. A finished basement that doubles as a workout space sits below, and the master bedroom is above it on the top floor.

Looking up in the 800-square-foot great room, featuring a 27-foot ceiling and floor-to-ceiling windows in one corner, Pedini points to three highway slabs that are the underside of his roof. Numbers scrawled on the concrete indicate where the slabs once sat as part of a temporary highway.

Pedini's wife, Cristina Perez-Pedini, also a civil engineer, designed the system that captures rain water for reuse on the garden atop the two-car garage. The couple moved in six months ago, after about 18 months of construction.

Pedini, Hong and Park hope the home is only a beginning. Under an idea Pedini calls "engineered precycling," they want a percentage of government-funded transportation construction contracts to require precycling.

But it may not fly in tradition-laced Massachusetts, where such projects have been hard sells.

Pedini had hoped to use Big Dig scraps to build a 24-unit apartment building on Modern Continental-owned property in North Cambridge. But residents and civic groups objected to the design. The City of Newton also said no to a boathouse proposed to be made with Big Dig leftovers.

The team hopes the state of Washington will show more interest. Officials are in the planning stages of a multibillion-dollar highway project in Seattle, replacing the Alaskan Way Viaduct. Pedini informally discussed it with the Washington Department of Transportation Secretary Doug MacDonald. Washington Project Director Ron Paananen sounded less optimistic, noting that most contracts give construction firms ownership of the materials.

Meanwhile, Pedini, now vice president for another major construction firm, Jay Cashman Inc., has spun off an affiliate company, ICON, to pursue his "precycling" goals. In addition to Seattle, Pedini hopes to sell the idea to federal transportation officials.

"Our goal is to get federal funding for a program like that, prove that it can be done, and then once we do it, try to standardize it so it becomes a rote portion for every megaproject thereafter," he said.

And they aren't done with the Big Dig, either. Hong and Park have drawn up plans for a Cashman headquarters. It would be a 30,000-square foot building using Big Dig beams and highway slabs, which they'd have to buy and transport from the storage yard.

"We're looking for an over-the-top effect," Pedini adds.