Or what about those first apartments many of us had (and some of us still do), called studio apartments, or bachelor apartments. One small room for everything, with a small bathroom.
Many empty nesters are down sizing too. But I doubt that many are moving into one room arrangements.
Meet Zaarath and Christopher Prokop -- and their two cats. They live in the smallest apartment in New York City, a 175-square-foot "microstudio" in Morningside Heights the couple bought three months ago for $150,000.
At 14.9 feet long and 10 feet wide, it's about as narrow as a subway car and as claustrophobic as a jail cell. But to the Prokops, it's a castle.
"When you first see it, the first thing you say is, 'Holy crap, this place is small,' " said Zaarath, 37, an accountant for liquor company Remy Martin. "But when I saw it, all I could think of is, I can do something with this. This is perfect for us. We love it."
The co-op is on the 16th floor of a doorman building on 110th Street, between Broadway and Amsterdam Avenue. But it's only accessible by a staircase on the 15th floor.
It has two small windows with views of upper Manhattan; hardwood floors; a tiny kitchen with a mini-fridge and hotplate; and a closet-sized bathroom with a shower, sink and toilet.
"I'm amazed we can fit two people and two cats in there," Zaarath said. "But it's harmonious at this point. I have friends who say they could never live with their husbands in a place this small. It's a good thing we like each other enough to live there."
The couple wakes up every morning in their queen-size bed, which takes up one-third of the living space.
They then walk five feet toward the tiny kitchen, where they pull out their workout clothes, which are folded neatly in two cabinets above the sink. A third cabinet holds several containers of espresso for their only kitchen appliance, a cappuccino maker.
They turn off their hotplate, and use the space on the counter as a feeding area for their cats, Esmeralda and Beauregard.
"We don't cook," Zaarath said, adding that their fridge never has any food in it. "So when you don't cook, you don't need plates or pots or pans. So we use that space for our clothes."
Once in their running attire, the two change the cat litter box (stored under the sink) and start their small Rumba vacuum -- which operates automatically while they're out, picking up cat hair.
They then jog to their jobs in Midtown, picking up along the way their work clothes, which are "strategically stashed at various dry cleaners."
Just in case the cleaners are closed, both have emergency clothes at their offices.
"I have a closet at my office," Zaarath said. "You don't want to be standing outside a closed cleaners at 8:45 in your workout pants thinking, 'Greeeeeat' . . . It's a great strategy. You always have fresh things to wear."