Here Come the Tall Skinny Houses: Assessing Single-Family to Townhouse Redevelopment in Houston, 2007-2020

Recent research has documented a recent and widespread boom in the construction of “townhouses,” or land-efficient single-family houses, both detached and attached, in Houston. Contrary to popular portrayals of Houston as a Wild West of unrestricted land use, this townhouse boom was in fact made possible by a deliberate reform in 1998, subsequently extended in 2013, that drastically reduced permissible minimum lot sizes citywide. In this article we build on this emerging body of literature to specifically focus on cases in which formerly single-family parcels were subdivided into small lots for townhouse construction between 2007 and 2020. We argue that Houston’s phenomenon of single-family-to townhouse, or what we stylize as “SF2TH,” redevelopment offers a glimpse of what other U.S. cities might expect to take place were they to repeal large lot single-family zoning and other binding restrictions so as to allow for the widespread construction of a widely desired small-lot single-family housing product in formerly low-density neighborhoods. We find that SF2TH redevelopment accounts for less than a fifth of overall townhouse development; that it tends to take place on larger lots in the urban core occupied by small, old houses; that it produces relatively reasonably priced houses; and that it predominantly takes place in neighborhoods that had higher than average house values prior to the period analyzed. The latter finding is inconsistent with a view of gentrification as a primary driver of SF2TH redevelopment. We also examine the pattern of “block votes,” or the pattern of usage of a petition mechanism that allows homeowners to opt out of townhouse development on their own blocks, and find that clusters of block votes generally adjoin clusters of SF2TH redevelopment but with relatively little overlap.