When Robert Ness went looking for a new home, he eventually decided on an 1,800-square-foot loft in Lake View with a balcony and views. He had to pass up other places he really liked: He couldn't even get into some of them, and once inside others he couldn't use most of the rooms. Because of a spinal cord injury 16 years ago, Ness, 37 and in television production, needed to be able to navigate his wheelchair from the street into his home and throughout the interior. "So many homes have steps, and the interiors don't have wide doorways," he said.

His loft, in a former department store, offers a straight shot from the curb to the lobby, into the elevator and up to his 4th-floor unit. Developer LR Development Co. adapted the design before it was built so a balcony would align with interior rooms and his bathroom would accommodate his wheelchair. Ness's situation is far from unique. Among the more difficult daily challenges for those physically disabled is getting into and around a home, whether it's their own or someone else's they visit.

Most laws that deal with accessibility generally cover only multifamily dwellings.

"Federal law requires only 5 percent of all new multifamily dwellings and federally funded single-family homes to be accessible [according to the guidelines of the Americans with Disabilities Act] through certain features such as elevators, ramps and wider than usual doorways," says Nadeam Elshami, press secretary to Rep. Jan Schakowsky (D-Ill.). These same laws have historically excluded privately funded single-family homes. Existing homes that require major renovations that will cost three-quarters of the home's total value can be counted in the 5 percent figure, Elshami says. Unless they can afford more expensive custom designs, many disabled people are shut out of the single-family home market, says Edward Steinfeld, director of the Rehabilitation Engineering Research Center on Universal Design at the State University of New York at Buffalo. The center promotes the concept of one set of universal products and buildings that everyone can use.

The concept of universal accessibility has now spawned its own term -- "visitability," which represents the attempt to incorporate into new homes such basic accessible features as a no-step entry; doorways with a minimum clear opening of 32 inches with the door open at 90 degrees; and access to a first-floor full or half-bathroom. (Universal design is the umbrella term that encompasses accessible and visitable features.)

Awareness of visitability is slowly growing as the number of grassroots advocates grows, as more information about it is disseminated, as some legislation is enacted, and as home builders act voluntarily with encouragement from municipalities.

Down the road, more builders may buy into the concept for another reason: to capture an expanded market as the older population increases in number and more seek to age in place, that is, to remain at home rather than move to assisted-living centers.

How significant is the need? More than 54 million Americans already are considered disabled under the definition set by the Americans with Disabilities Act, which says disability is an impairment that limits at least one major life activity -- walking, for example. That's roughly 20 percent of Americans, and the University of Michigan Initiative on Disability Studies estimates by 2010 the figure will hit 50 percent.

About 3 percent of the country's population uses a wheelchair, walker or cane, says Bruce Deason, formerly senior director of governmental affairs at the Attainable Housing Alliance in Lombard, which represents builders and developers in an eight-country metro area.

But Deason says that the seemingly small number is deceptive because it fails to take into account other factors that could cause an uptick: (1) the suddenness with which a disability may need to be dealt with; (2) the need of those not wheelchair-bound but who have difficulty walking or using stairs to get around; and (3) the greater cost to retrofit an existing home rather than building in features from the get-go.

Jennifer and Daniel Thomas found out about higher costs after a long search to find a ranch house in Chicago to accommodate Jennifer's wheelchair. The location, size and price were right, yet a two-step entry made it necessary for Jennifer, who has cerebral palsy, to have help getting in and out. "It was embarrassing to ask," said Jennifer, personal assistance coordinator at Access Living, a Chicago organization that provides services for the disabled.

For the first year, the couple couldn't afford a ramp, estimated to cost $2,500. They finally found a contractor who charged $930 to install one.

When visitability components, including a no-step entry, are built into a new home, however, the added cost can be less than $500, Steinfeld says. "Many won't agree with this number because they think in terms of higher renovation costs rather than redesigning the house the right way from the beginning," he says.

Retrofitting can add between $5,000 and $10,000 for basic visitability features and more if an elevator is included, Steinfeld says. In addition, changes may hurt a home's curb appeal, says Karen Tamley, program director at Access Living, impeding its marketability.

If advocates have their way, laws may change the landscape, literally. On the legislative front, Rep. Schakowsky introduced the first federal visitability legislation, HR 5683, last fall and plans to reintroduce it in the new Congress. It would require all newly built single-family homes and townhouses receiving federal funds to meet basic visitability standards. The law, Schakowsky's staff emphasized, will not amend the Americans with Disabilities Act.

Certain Chicago-area communities have been in the visitability forefront. Since last April 8, Naperville has required builders to include basic visitability features in their single-family-home plans in order to get building permits. "There was a lack of housing stock for those in wheelchairs," said William Malleris, chairman of Naperville's Fair Housing Commission and a developer, who uses a wheelchair.

Among the required features are a wall reinforced to support grab bars in a bathroom and wall switches located no higher than 48 inches from the floor and receptacles at least 15 inches above the floor for easy wheelchair access. Naperville does not require no-step entries because of the area's elevated foundations, which would make building difficult and costly.

The Village of Bolingbrook's administration took a voluntary approach by "strongly encouraging" builders through education about the need for visitability features, said Dan Buonamici, building commissioner in the building division. "All are complying," he said.

Lombard-based Town & Country Homes used basic visitability features at its Southgate Park, a development of 283 two-story houses in Bolingbrook. "We'll see whether such changes should become standard," said Steve Sandelin, vice president of product design. He estimates square footage added to halls and the bath to accommodate widers doors adds $1,000 to $1,500 to the cost of each home -- without the no-step entry. In that price, the houses also include other features such as proper outlet and switch heights and bathroom wall reinforcement.

Lakewood Homes Inc. also incorporated visitability features -- including a no-step entry -- at its Lakewood Ridge development of 500 houses in Bolingbrook. Doing so added $2,200 to the cost of each home, , said Christopher P. Shaxted, executive vice president.

Making houses visitable in the city is tougher than in the suburbs because soil conditions and height restrictions make it harder to dig deeper and build higher, says James Letchinger, president of JDL Development Corp. He would prefer that the city be more flexible about height variances in certain neighborhoods.

That may not happen immediately, but the city is rewriting its building code to require that 10 percent of single-family homes or townhouses in a planned development be visitable and 10 percent be adaptable.

For now, however, most builders take the position that the market should drive demand. "We're happy if somebody comes with a custom request, but we haven't gotten any, except for an elevator," says Julie Jacobs, director of marketing for Jacobs Homes in Deerfield.

Momentum may increase once the National Association of Home Builders (NAHB) takes an official position. "We need to develop a response because more builders are getting calls," said Jeffrey T. Inks, assistant staff vice president in construction, codes and standards. "I think our group will oppose mandatory requirements, but encourage voluntary efforts." He said last week that a policy would probably be presented to the NAHB board in May.

The strongest incentive may be the cost if changes are not made, explains one early advocate, Eleanor Smith, head of Concrete Change in Atlanta, where a decade ago public housing was required to be visitable. "The cost to avoid doing so will be huge if the increasingly older population has to move to nursing homes," she says.