Our cities are going single

Wonk Blog, Washington Post -We're increasingly a nation of single people, but we're still living, quite literally, in a world built for families.

The disconnect between these two trends is particularly acute in big cities, as the Furman Center points out in a new research brief. In New York, Austin and Denver, nearly 57 percent of adults were single in 2010 (although not necessarily living alone). In Washington, D.C., that figure is a whopping 71 percent.

But none of these cities have anywhere near enough small-sized housing to accommodate them. That means that a lot of people are probably living with unrelated adult roommates who'd prefer to live alone (half you people in D.C. group homes?). And it means that some people who do live alone are likely paying more for space they don't want in a large one-bedroom because there aren't enough alternatives in studios and efficiencies.

Changes in demographics and social norms invariably occur faster than changes in the built world around us. It took decades, even more, for Washington and New York to grow up into the places they are today. But, as Vicki Been, Benjamin Gross and John Infranca at the Furman Center point out, a lot of cities are also actively making it hard for the housing supply to adjust.

The rise of singles calls in particular for more micro housing: apartments the size of studios or even smaller, and "accessory dwelling units" (think in-law cottages or garage apartments) that might be built in the back yard of existing homes. It also calls for a different model of housing where, for instance, four singles might share a communal living space adjacent to their separate units instead of each having their own living room.

Neighborhood opposition and existing regulation make this kind of housing hard to build in most cities, though. Parking requirements, for example, often mandate that new housing come with new off-street parking spots, too. But that rule is impractical for someone who wants to rent a cottage in her backyard. And it makes projects financially unworkable for a developer who wants to build an apartment full of micro units next to a train stop for residents who don't own cars.