(MONEY Magazine) – When Brett Long and Megan Clinefelter bought their 1925 Minneapolis bungalow five years ago, there was little work left to be done to it. The previous owner, an architect, had almost completely rehabbed the house. One exception: He hadn't touched the basement, with its ratty carpet, brown paneled walls and exposed pipes. Noting the potential and the fortune of having 7½-foot cellar ceilings, Long decided to take on the task himself. "We wanted a comfortable family room where we could hang out with our dog Nellie and read, listen to music or watch TV," he says. In just seven months the do-it-yourselfer made it so. The 700-square-foot floor now has an L-shaped living area, complete with a gas fireplace, custom cabinetry, an exercise room and a separate laundry room. Plus, the space incorporates some of the modern materials used upstairs, like metal and slate. The new lower level is cozy and contemporary--not to mention, says Long, "a great place to roll around on the floor with Nellie."

Cozy chic To create a more open space, Long spent a week tearing out pipes and walls; he then had the posts removed and a support beam installed ($3,200). He also put in bigger windows to let in more natural light ($720). The couple splurged on the room's centerpiece, a gas fireplace with maple mantel, slate surround and poured-concrete hearth ($5,400).

Modern twist To continue the design theme from upstairs, Long hired the home's former owner to construct patchwork metal walls, right, and a cover for the support beam, above ($2,700).

THE NUMBERS

BOUGHT IN 2001 FOR

$300k

RENOVATION COSTS

$42k

WHERE DID IT GO? The biggest chunk ($32,700) went to hiring pros for the complex jobs. The rest paid for materials that Long used himself. Estimated savings from his DIY work: $25,000.

MARKET VALUE TODAY

$385k

WORTH IT? "Normally, finished basements don't add value," says local realtor Mary Alice Kopf. "But this one is well done. It adds a lot of living space, and it ties the whole house together." It could add $70,000 now--and more when the market rebounds.