threefamily

Threefamily, sometimes written three-family, is a term used to describe a dwelling designed to house three separate family units. In real estate and urban planning, the label refers to a single property configured to accommodate three distinct households, typically with separate entrances, kitchens, and utilities. Configurations vary by region and property type.

Architectural forms include triplexes, three-unit buildings, or triple-decker houses, which may be three stories tall or arranged as connected side-by-side units. The term is especially associated with multi-family housing in certain markets, such as the triple-decker houses common in New England cities.

Threefamily properties are often pursued for rental income, owner-occupant strategies, or as an affordable housing option. They require careful management, financing, and compliance with local zoning and occupancy rules. Utilities may be individually metered or shared, depending on the layout.

History: Multi-family housing with three units emerged in the 19th and early 20th centuries to accommodate growing urban populations. In the United States, the three-decker became a recognizable form in Boston, Worcester, and other Northeast cities, reflecting immigrant- and labor-market needs.

Contemporary usage: In real estate listings, threefamily is used as shorthand for a three-unit dwelling. Lenders often offer specific multi-family loans, and zoning codes may regulate the number of units per building and family occupancy. The term is largely descriptive rather than a distinct legal classification.