If you’re planning to stay in your home well into your golden years, doing some renovations before you retire can help make your house safer and more accessible.

Nearly 90 percent of people over age 65 want to stay in their homes for as long as possible, according to research by the National Conference of State Legislatures with AARP Public Policy Institute. But many wait too long to make renovations that facilitate aging, says Marianne Cusato, an adjunct associate professor at the University of Notre Dame’s School of Architecture.

“You don’t wait until you have mobility issues to make changes to your house,” she said.

Some pre-emptive renovations make more sense than others. Installing ramps to accommodate a wheelchair, for example, is expensive and potentially unnecessary.

Still, some universal design changes and remodeling projects will help you grow older in your home comfortably and safely.

1. A walk-in shower

Climbing over the edge of a bathtub can be difficult. A walk-in shower can solve this problem, while making your bathroom look more modern, said Joanne Theunissen, chair of the National Association of Home Builders.

Cost: Tearing out an old tub or shower and building a walk-in shower can be expensive. Although some walk-in shower kits start as low as $200, you need to know plumbing and framing to do the work yourself. Having a kit professionally installed will add $750 to $2,500 to the cost, depending on the bathroom layout and plumbing requirements. For a professionally installed custom shower, expect to pay $6,500 to $15,000 or more, depending on the size of the shower and the materials.

2. Grab bars

Every 11 seconds, an older adult is treated in the emergency room for a fall, the National Council on Aging reports. Adding grab bars in select areas can help reduce your risk of falling.

But “just having a grab bar in every room of your house for the sake of having one doesn’t make a whole lot of sense,” said Steve Hoffacker, a certified aging-in-place specialist and instructor. “You have to think strategically about where you want to install them.”

Your main shower should have one, even if it’s a walk-in. Also consider putting a grab bar by the door you use most often. “When you’re trying to balance packages or grocery bags that you’re holding, it’s nice to have something to hold onto other than the door handle,” Hoffacker said.

Cost: Grab bars generally require professional installation. On average, it costs $140 to have three grab bars installed, according to Fixr.com.

3. A first-floor master suite

One of the best ways to age-proof a house is by having a master bedroom and a bathroom on the first floor, said Mark Hager, founder of AgeInPlace.com.

Cost: If you don’t already have first-floor space that you can turn into a master suite, you’ll have to build an addition. It’s expensive to expand your home’s footprint: Homeowners spend an average of $80 to $200 per square foot, HomeAdvisor said. So if you’re building a 250-square-foot bedroom and bathroom, it can cost $20,000 to $50,000.

“It’s a big expense,” said Hager, “but it really pays.”

4. Door lever handles

Nearly half of people 65 years or older have arthritis, the Centers for Disease Control and Prevention reports, which can make even grasping a doorknob painful. One solution: Replace doorknobs with lever handles.

Cost: At Home Depot, stainless lever handles start at about $5 apiece. There’s no need to hire a pro. This is an easy DIY project.

5. Nonslip flooring

Floor surfaces can be slippery, so some homeowners cover hardwood or laminate floors with rugs. But “rugs can create a hazard, because they change the grade of the floor,” said Cusato.

She recommends installing nonslip flooring or carpeting in every room but the kitchen, bath and mudroom. While carpet can “help cushion a fall much better than a hard surface,” Cusato cautions that most wheelchairs and walkers can’t easily roll over thick carpeting, so make sure it’s no higher than a half-inch and the padding underneath is firm.

Cost: Many factors must be considered: room size and shape, carpet material, furniture removal, labor. But high-quality carpeting and padding can be installed for $19 to $38 a square yard.