Boston: Tripledecker of the Universe

So I'm not just imagining it. According to the last Census, 26 percent of all homes in Boston are in three- or four-unit buildings, the highest share among the 50 biggest cities in the US. (Chicago is second, with 14 percent, and Detroit is last, with 3 percent.) Unfortunately, the Census doesn't distinguish between tripledecker houses and townhouses that have been divided into three apartments, so I can only cite my own eyes as proof that there are a lot more of the former. I can say that we rank pretty low in single-family townhouses. Only 4.9 percent of the homes in the Hub fit this category, which is 31st among the 50 largest cities -- between El Paso and Memphis. In Philadelphia, 60 percent of all single-family homes are attached to other buildings (but have floor-to-roof walls separating them), and in Baltimore the figure is 52 percent. Then there's a steep drop-off to third-place Washington (26 percent). Obviously, single-family townhouses are extremely expensive in Boston, but other expensive cities (including New York, San Diego, and San Francisco) have a lot more of them than we do. I still get the sense that medium-height compact housing is a rare commodity here, and that the scarcity is one reason we have so few commercially vibrant neighborhoods. You can look up the data here.