The Basement Steps Out Into the Light

SEATTLE

Underground Retreats A skylight illuminates a Portland basement.

WHEN Frank Fuoco and his partner, Benjamin Liu, began planning a new master suite for their 1922 brick bungalow in north Seattle, they thought about building up or out.

Instead they went down. To the basement.

There, in place of a dank warren of concrete walls, a washer and dryer, and cluttered storage, they now have a serene bedroom and a bathroom trimmed in green tile and Douglas fir, warmed by radiant-heat floors and flooded with light from large windows set in wells.

The addition, which was completed this spring, is "the most comfortable room in the house," Mr. Fuoco said. He and Mr. Liu and their 7-year-old son, Cale, "all pile on the bed down there to watch television," he added, "because it's so cozy."

Basements, of course, have long served as funky, out-of-the way living spaces, places for wet bars, pool tables and rec rooms - even, on occasion, well-appointed guest rooms for in-laws. Yet in most parts of the country, they have typically been seen as too cold, damp and dark for full-time habitation. But improvements in construction methods, insulation materials and heating and ventilation technology in recent years have made it possible to do more with them, and have led increasing numbers of people to turn them into retreats, with main-floor elements like full bathrooms and even master bedrooms.

And the cost of real estate, which has remained astronomical in much of the country even as markets have softened, has pushed many homeowners to squeeze every habitable square inch out of a house. "In a lot of houses, the basement is underutilized," said Greg Bjarko of Bjarko Serra Architects, the Seattle firm that designed the basement suite for Mr. Fuoco and Mr. Liu. "People are starting to capture that space and really make it a primary part of the house."

But a number of challenges come with this new focus on creating comfortable rooms in what was once leftover space. "If all you're using the basement for is a utility room or something like that, then a little dampness on the floor is not a big deal," said Scott Gibson, the Maine-based author of "Bathroom Ideas That Work" and a former editor of Fine Homebuilding magazine. "But in a finished space, you have building materials and finishes that are susceptible to water damage, to say nothing of mold."

So for starters, basement suites need protection from damp, which can mean installing improved drainage around the exterior perimeter of the house and adding waterproof membranes under new flooring and walls. And depending on plumbing, a pump may be required to make the drains work in showers, sinks and toilets.

In much of the country, carcinogenic radon gas is also an issue, and extra ventilation or barriers may need to be installed to remove or block the gas. (Radon may be detected either with a kit or by a testing company.)

Extra infrastructure - a stud wall, built-up floors and other construction - can reduce the available living space, a problem that designers have developed various strategies for handling. In Mr. Fuoco and Mr. Liu's basement, for instance, workers demolished the original concrete floor and carted it out, then poured a new slab in its place, instead of installing the new floor on top of the old one. That kept the volume of the room essentially the same, but made it possible to add radiant floor heat: warm water is piped into the new floor through flexible tubing attached to a water heater.

Because below-ground spaces tend to be more cramped than those on other floors - no matter what kind of space-saving construction strategies are used - most designers who do basement conversions come up with other tricks to make them appear bigger. Vern Yip, an Atlanta-based interior designer who was a regular on the TLC television show "Trading Spaces" and is now a judge on HGTV's "Design Star," recommends using a monochromatic color scheme to hide the intersection of walls, floors and rooms, which he said visually opens up the space.

"These spaces also tend to be light-challenged," Mr. Yip added. "Overhead lighting is critical - you want to create that sense of light coming down from above," to mimic natural light. Mr. Yip said he prefers to use bright halogen or PAR (parabolic aluminized reflector) lights, because they have a whiter, more day-like light than other bulbs. But because basement ceilings are often low, he uses lights that can be installed on the walls or recessed in the ceiling, rather than hanging fixtures.