Wow, check out this cool animated .gif time series. Via Planetizen, it’s a “housing typography” map of the Twin Cities metro showing two-decade periods. The map comes from a report by a California economist named Issi Romem called “America’s New Metropolitan Landscape.” It makes an argument that US cities are dominated by what Issi calls a “dormant suburban interior.”
By dormant, Romem is referring to a areas with a lack of new housing construction, and he made an amazing series of US metro maps to prove it.
Here’s the Twin Cities:
Here’s an explanation of the dark blue / “almost no construction” area:
The following map colors the residentially developed footprint of the Los Angeles metro area as of 1960 according to the dominant type of new housing built there during the 1940s and ‘50s. It distinguishes between single-family homes in light blue, 2 to 49 unit structures in orange, and 50+ unit structures in red, and assigns each Census tract a color based on the type of housing that accounted for the most new homes during the period.
The map reserves an additional color, dark blue, for areas that produced no new housing at all, or that produced it at a negligible pace, defined as less than 0.1 new homes per acre per decade. This pace is equivalent to less than one new home per acre per century, which means that transitioning a neighborhood from a stereotypical suburban density of 4 homes per acre to a borderline walkable one of 10 homes per acre at this rate would take more than 600 years.
The point of the paper is that, outside the greenfield fringes, it’s only very few areas in most US cities where any growth housing is happening at all.
Romem goes on to explain why in so much of our US cities, including much of the Twin Cities suburbs, the construction of any new housing has stopped. It’s a series of causes revolving around local land use controls, and Issa is arguing that we need to shift this political landscape if we’re going to make any progress towards solving the housing crisis.
Here’s the key point:
While cities continue to fight the battle for development in dense hubs, they also question the de facto exemption granted to low-density suburban areas from the onus to produce more housing. The dormant suburban sea is so vast that if the taboo on densification there were broken, even modest gradual redevelopment – tearing down one single-family home at a time and replacing it with a duplex or a small apartment building – could grow the housing stock immensely.