Betsy McCann and her husband, Jim Forbes, often worried that his mother was growing isolated in her Los Angeles-area home. At 90, Lois Brokus had stopped driving and was sometimes afraid to be alone in her house.
Jane and William Merrill also decided that they didn't want his mother living on her own anymore. Then 81, Jane Merrill, who shares her daughter-in-law's name, was still active but in need of companionship.
Both families considered nursing homes, assisted living and retirement communities. In the end, they came to the same conclusion: Their homes were the best place for their mothers. But they needed more home.
So McCann and Forbes added a 400-square-foot bedroom and bathroom to their Escondido, Calif., home; the Merrills converted a two-car garage at their 8-acre spread in Carmel, a suburb of Indianapolis.
Now, both older women live with their adult children, with a large degree of independence and privacy.
Although it isn't for everyone, it is a choice many families are making. Home builders across the country say they are getting an increasing number of requests for such additions, known as mother-in-law suites , granny flats or accessory dwellings.
According to the National Association of Home Builders, 62 percent of builders surveyed were working on a home modification related to aging in 2010. About one in five builders added an entry-level bedroom.
About 3.5 million American households last year included adult children and their parents -- a number expected to rise as the country ages and baby boomers move into retirement, said Nancy Thompson, an AARP spokeswoman.
To accommodate the growing demand, AARP teamed up with the home builders' association to create a designation for Certified Aging in Place Specialists,