“Missing” No More: Planners Should Harness Private Developers to Build Middle Housing

Although land use planning in the United States has long privileged single-family homes, the dominance of single-family zoning is weakening. At least eight states have passed laws opening single-family neighborhoods to accessory dwelling units and, in some cases, to middle housing, such as townhouses, duplexes, triplexes, and quadplexes. Opponents of laws liberalizing single-family zoning often seek to prohibit for-profit developers from densifying single-family neighborhoods, by restricting development to owner-occupiers. Often these opponents invoke concerns about gentrification and social equity. But for recent zoning reforms to put a meaningful dent in the housing affordability problems confronting many regions, the planning profession must accept that the physical transformation of neighborhoods at scale will require significant, though by no means exclusive, involvement of for-profit builders. In this Viewpoint we explain why the relevant empirical evidence from cities such as Houston (TX), Portland (OR), and Auckland (New Zealand) indicates that single-family zoning reform can foster more affordable types of housing through for-profit development, while allaying fears concerning gentrification and displacement. Cities and states should promote equity and neighborhood stability through tools such as tenant protections, but they should eliminate owner-occupancy restrictions and other regulations that bar for-profit developers from building middle housing.