An accessory dwelling unit of my own.

• Author: Rundles, Jeff
• Position: RUNDLES WRAP UP - Trends of family room - Column

WHEN I WAS ABOUT 10 YEARS OLD MY mom and dad decided to move the family into a larger home, and they got a rather stately colonial that would be their home for 40 years. For decades, that house had been the ideal configuration for a modern home, but in the early 1960s when we acquired it, my parents decided it needed a "family room," which they promptly added. None of my friend's homes had family rooms.

Of course, 10 years later every house had a family room, and 10 years after that began the craze for a "great room." I remember it struck me funny when I first got married in the 1980s and in my in-law's rather spacious home, no one hardly ever ventured into the "living room." By the late 1990s the living room in most new designs became little more than an offshoot to the entry. Over the same time kitchens morphed from closet-like utility rooms into centerpiece entertaining spaces.

Times and tastes change. Our parents' generation, emerging from The Great Depression, favored wall-to-wall carpeting--a sign of "making it." We Baby Boomers pulled up the carpet in favor of the hardwoods.

The latest housing trend, however, isn't faddish or a show of upward mobility. It is, rather, a tangible economic statement on the future of the middle class, and not altogether a good one.

I recently saw an advertisement for a Lennar Home called the NextGen, which features a separate suite with a private entrance and access to the main house, billed as a place for an aging parent or adult kids. During some research I discovered that these "granny" suites or "multigenerational homes," whether attached or built as detached cottages, are referred to as "accessory dwelling units" (ADUs) and are quite contentious in cities across the country.

No one, it seems, minds the concept of junior or granny coming to live in the family home, even in a separate space. However, what riles the zoning police--and apparently the neighbors--is the idea that these spaces could be rented to anyone as a way for the homeowners to generate extra income.

ADUs are said to increase the value of a home in some areas of the country by as much as 60 percent. Indeed, some homebuilders pitching the idea are targeting aging Baby Boomers on fixed...