Another term sometimes used to describe housing for households with incomes above federal income limits but who are finding it difficult to afford housing on the private market is “missing middle” housing. The term was coined by Opticos Design founder Daniel Parolek in 2010 to define a range of multi-unit or clustered housing types -- compatible in scale with detached single-family homes -- located in walkable neighborhoods, which help meet the growing demand for walkable urban living. See website: https://missingmiddlehousing.com/
Many planners refer to missing middle housing as types of residential structures that provide a choice of housing between single-family detached structures and apartment buildings. This term may be used without regard to the income of the households occupying the housing.