With buyers looking for homes that will be usable for years as their family needs evolve, design pros are stepping up to meet the challenge with a variety of flexible solutions.

When Creighton and Tracey Gibson built a ranch 15 years ago, Creighton’s job as owner of a franchise that offers nonmedical care and companionship to seniors made him sensitive to his own aging family members’ needs. Accordingly, the couple added some features to their North Carolina home to accommodate them when they moved in.

First, an extra bedroom with kitchenette and a bathroom with grab rails were put in when Creighton’s father moved in after a fall in 1998. After he died and Tracey’s mom, an amputee, couldn’t manage alone, the couple built a ramp at their front door for her wheelchair. The Gibsons have found the arrangement offers benefits to each generation, including for their 11-year-old daughter, who gained a live-in babysitter when she was young and now can offer companionship as she gets older.

Housing aging parents for health, safety, or to avoid loneliness as they’re living longer isn’t the only reason that home owners are altering floor plans:

▪ A rising immigrant population whose cultural traditions often encourage everyone to live under one roof is making the multiple-generation household more common.

▪ The difficult economy is spurring college graduates to do what was once unthinkable — move home and reclaim childhood bedrooms until they land a job or save enough money to be on their own. Ditto for young divorced adults, sometimes with a child in tow.

▪ The tough resale market is convincing empty-nesters to stay put and remodel homes to maximize unused space, including spare kids’ bedrooms.

Because of the differences in needs, ages, traditions, budgets, and property types, there’s not a single layout that works for a large cross-section of consumers, says Brian Brunhofer, president of Meritus Homes, a home builder in Deerfield, Ill. As a real estate professional, your job is to help buyers and sellers assess housing options for now and later with three major objectives in mind:

Incorporate Universally Appealing Universal Design

Any home — newly built or remodeled — should consider this concept as much as possible since it strives to make a home safe and useable for a variety of ages, abilities, gender, budgets, and physical challenges, says John Salmen, member of the American Institute of Architects and founder of Universal Designers & Consultants in Takoma Park, Md. Among its prime tenets:

▪ Easy circulation: Navigating space freely is key, whether people move among different levels or spaces on the same level, Salmen says. Doors and openings should be at least 32” wide for wheelchairs and walkers to get through. Elevators can eliminate stair climbing for those physically challenged or even for home owners needing to carry heavy groceries up stairs. Adding a two-stop model in an existing house might cost between $20,000 and $25,000, but leaving a 4’ by 5’ shaft, so equipment can be installed later if needed, would cost less than $5,000 initially, says Richard Bubnowski, design principal of his eponymous firm in Point Pleasant, N.J.

▪ Good illumination: Aging eyes need three to five times more light than people do at 18 years of age, says Salmen.

▪ Non-slippery floors and low-piled rugs: These help people of all ages avoid falls.

▪ Easy room and appliance access: Instead of knobs, levers facilitate opening doors for young and arthritic hands. Touch faucets allow easier access to water, particularly when hands are sticky or fingers also are arthritic.

▪ Movable storage: Placed under kitchen countertops, these can be rolled away to allow home owners to sit in a traditional chair or wheelchair.

▪ Zero-step entrances: Whether crossing a main door or walking into a shower, these make traversing spaces carefree.

▪ Discreet grab bars: These eliminate an institutional look and can mimic wainscoting or any trim, says Lake Bluff, Ill.-based builder Orren Pickell.

Maximize Existing Space to Avoid Expensive Additions

Before adding space, home owners should make better use of what they have, says designer Marianne Cusato, author of Get Your House Right (Sterling Publishing, 2008). “Perhaps there’s stuff that can be put away with affordable storage purchased at places like IKEA, or a rarely used dining room that can become an office,” she says. Other ideas include:

▪ Transforming basements and attics: When houses include these levels, typically unfinished, converting them can cost less than adding on to a first floor, says Pickell. The main expenses may be a nicer stairway; stronger floor or subfloor; better insulation, ventilation, and windows; plumbing for a bathroom; and an outside egress to meet building codes.

▪ Converting dens, family rooms, and garages: These main floor spaces can be remodeled into a bedroom for full- or part-time use for someone not able to climb stairs, and a nearby powder room can be remodeled to accommodate a shower if there’s space, says Elizabeth M. Sorensen with Dale Sorensen Real Estate in Vero Beach, Fla. When a door to the outside can be built, the suite becomes more desirable and private, says Brunhofer. Adding this type of suite can cost less than a year at a nursing home, says Michigan designer Leslie Hart-Davidson. “Home owners should think in terms of long-term savings,” she says.

▪ Rethinking empty bedrooms: For home owners whose children aren’t returning, Hart-Davidson transforms bedrooms into gyms, hobby rooms, offices, and walk-in storage.

▪ Melding indoors and outdoors: Homes become more usable and enjoyable by opening them to the outdoors through large windows and walls that provide a visual and physical connection, says Irvine, Calif.-based architect Robert Hidey. The outdoor areas themselves become more room-like and functional when designed with distinct areas to cook, sit, and dine, preferably with a “roof” and “walls” to screen hot sun, rain, and bugs, he says.

Build New to Meet Needs for the Long Haul

Constructing a new home from the get-go to meet a range of life stages helps avoid expensive alterations. Among the most usable designs:

▪ Hip ranches: Popular after World War II as new suburbs sprouted, they’re attracting attention again since they offer a cost-effective plan and main-level master suite. Brunhofer estimates the layout may run 10 to 15 percent less than a comparable two-story home. His firm sometimes adds a second master bedroom for future family needs.

▪ Loft-style plans: Whatever the house style, Bubnowski advocates one open sweep inside for living, eating, and cooking. So does Colleen Reardon, manager and sales associate at K. Hovnanian Homes in Orlando, Fla., which conducts extensive research and has seen interest also in open ceilings and bigger living spaces.

▪ The “New Economy Home”: Cusato’s efficiently scaled 1,771 square-foot, two-story “New Economy Home” was planned with the latest demographic trends in mind. The house is compact, so it costs less to build and is easier to maintain than most other homes, and features one master suite upstairs and a second one downstairs off the kitchen with an adjacent bathroom and back door to a porch and the outdoors.

▪ Bonus rooms: Once built above a garage for myriad uses, the bonus room is back, as it’s able to change functions as family needs demand. Today it’s a playroom; tomorrow it’s a home office or gym.

▪ Ancillary cottages: When land, budget, and codes permit, some home owners build a separate structure away from the main house, says Cusato. These detached bungalows or casitas are a way to gain a separate living or work space for family or a hideaway for guests who stay a while, says Hidey.