Change tags along with birthdays. That is what Baby Boomers are learning as they swell the ranks of seniors. Changing gears from raising families or non-stop working to a new chapter in active living often calls for modifying homes to live more comfortably as bodies age.

Retirement communities here provide sterling role models in ageless or “universal” design. Ideas from newly opened The Mather, Presbyterian Homes and Three Crowns Park offer ideas in universal design that can be adopted or modified by homeowners and condo-owners. Universal design enables people to perform daily routines with greater ease and safety as they age.

The demand for such modification is exploding. According to the U.S. Census Bureau, the elderly population will more than double from now until 2050, when 80 million adults (one out of five) will be over the age of 65.

Adaptation can mitigate the physical and mental changes that accompany aging. Diminished gait may require thinner padding and less pile in carpet. Weakened eyesight benefits from flooring with more contrasts in colors and patterns. Opening a door with stiff fingers is easier with a lever door handle than a knob, a key card instead of a brass key. Shaving and brushing teeth with a bad back are easier if the bathroom counter is raised a few inches.

Adapting a home or apartment to be senior-friendly can be a challenge, says Susan J. Morse, executive director of Three Crowns Park in northwest Evanston.” Widening a doorway or installing barrier-free shower entrance can be expensive and difficult if the home is older,’’ she said. But modest changes – different door hardware and single-lever water controls on faucets – are possible and effective.

The Mather, located just east of downtown, offers up to 50 floor plan options to residents and prospective buyers of the 141 units. The staff asks prospective residents questions about lifestyles, routines and habits. “We want to understand their daily lives and which household activities are now more challenging. Those answers help us to accommodate them,’’ says Gale Morgan, vice president of sales.

The Mather complex will include two apartment buildings, with apartments and public spaces featuring subtle design details that create comfortable environments effective for everyone regardless of age or physical condition, Ms. Morgan added.

The goal of universal design is function and flexibility for all, says Nancy Tolan, architect and vice-president of facilities, planning and construction at Presbyterian Homes, also in northwest Evanston. “We want people to function independently as they age. That means doing their daily routines with ease.’’

The Mather, Presbyterian Homes and Three Crowns Park offer ideas and examples in how to live well with comfort and safety. Their design research into tomorrow’s lifestyle needs is on-going. “The demand is there, so are the solutions,” adds Ms. Morgan. The following are some suggestions for ageless design.

Entrance doors/hallways/public areas: All three retirement complexes feature lobbies that are wider than average to accommodate people with assistive devices such as walkers, and feature sliding glass doors with chair-level assist buttons. Hallways also feature a single handrail and motion-sensor lighting. Handrails look like molding.

Bathrooms: The turning girth (or width) that frustrates users of public stall bathrooms gets extra width in public restrooms and bathrooms. Grab bars can function and look like towel racks. Easy-to-grab lever handles on faucets, zero thresholds on showers, and showers with hand-held wands and temperature controls with large symbols can assist everyone.

Hardware (doors, cabinets): Many doors feature levers and grips instead of knobs, and pull-out kitchen shelving on casters. Such features make opening a cabinet easier for people with reduced upper body strength or arthritis. In dining rooms and restaurants of The Mather, there are nooks where assistive devices can be stored.

Windows: Casement windows open with of circular motion of a lever – no longer is Herculean strength required to yank a window up or down.

Living room: Fireplaces add atmosphere and warmth. But for someone with diminished eyesight or memory problems, it can be a source of concern and worry, especially to children of residents. A solution is an enclosed gas-powered fireplace that goes “on” with a flip of a switch. Electrical outlets are positioned higher than above-floor level for ease of reach. Peep holes into each door are designed for regular height and at chair-level. “No one has to tip-toe to see who’s at the door,’’ says Ms. Morgan. Heating/cooling controls are also mounted at chest-height.

Color schemes: Contrasts in colors, patterns and textures in flooring are critical for individuals who are vision-challenged. There are no steps or raised thresholds.

Lighting: Key to atmosphere and doing tasks is lighting, says Ms. Tolan. She gauges light levels and intensity on how light reflects off surfaces. “With a darker finish, you need more light.’’

Kitchen/utility rooms: All controls on the kitchen stove are at waist-level in the front of the appliance to minimize reach and danger of getting burned. No slamming of the stove door, because it is weighted. Washers and dryers are front-loading styles.