Senior News reports that the American Association of Retired Persons (AARP) is trying to determine what kind of housing Boomers will want in the next 20 years, and what they can afford.  The average age of people needing assisted-type care is 85, so that leaves a potential 20-year span for Boomers to dwell somewhere.  Harvard University’s Joint Center for Housing Studies report from 2003 revealed 55 percent of seniors had incomes of less than $15,000 a year, and only 23 percent had annual incomes of above $25,000.  Kelley Hrabe, president of a firm that specializes in affordable elderly housing, says lower and middle-income housing is expected to dominate the market in coming years.  His company’s newest project is small two-bedroom units that rent for $475-775 a month, and there is a 350-person waiting list.