Glossary

A development containing a defined percentage of low- and moderate-income dwelling units. This term includes, but is not necessarily limited to, the creation of new low- and moderate-income dwelling units through new construction, the conversion of a nonresidential structure to a residential structure, and/or the gut rehabilitation of a vacant residential structure.

Source: A Planner's Dictionary, The American Planning Association

Missing middle housing is a range of house-scale buildings with multiple units—compatible in scale and form with detached single-family homes—located in a walkable neighborhood. 

Source: missingmiddlehousing.com