The Missing Middle
This pattern is shaped by
Problem
When zoning allows only detached single-family homes or large apartment buildings, a vast range of housing types — duplexes, triplexes, fourplexes, cottage courts, townhouses — is forbidden, prices are inflated by artificial scarcity, and neighborhoods are segregated by income.
Evidence and Discussion
The term "missing middle" (coined by Daniel Parolek in 2010) describes housing types that were common before 1940 and are now effectively illegal. In many North American cities, over 70% of residential land is zoned exclusively for single-family detached homes.
The evidence is compelling. Minneapolis eliminated single-family-only zoning in 2018, allowing triplexes on any residential lot. Oregon legalized duplexes statewide in 2019. California permitted lot-splitting and duplexes via SB 9 in 2022. In each case, neighborhoods absorbed gentle density without losing their character.
The key is *house-scale* — these buildings look and feel like large houses, not apartment complexes. Two to three stories, with front entries, porches, and gardens. Sixteen to thirty units per acre, not sixty.
Therefore
in any residential neighborhood, allow and encourage building types between the single-family home and the apartment building — duplexes, triplexes, fourplexes, cottage courts, and townhouses — at densities of sixteen to thirty units per acre. These buildings should match the scale, setback, and materials of existing houses. They should have individual entries from the street or a shared courtyard, not a common corridor.