“The modest increase in housing production can be largely explained by how marginal many of these missing middle reforms have been.
Often, cities will legalize missing middle housing without allowing the new multi-unit buildings to be much larger than the single-family homes they’d replace. That means a builder faces all the costs of tearing down an old unit without the ability to add much additional revenue-generating floor space.”
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“Another problem facing missing middle home construction is a whole thicket of nonzoning rules and practices that assume new construction will either be single-family homes or larger apartment buildings.”