Tripledeckers, also known as three-deckers or three-families, are a type of apartment building that is common in cities such as Boston. These structures are so-called due to their three floors, each containing a separate apartment unit. The name Tripledeckers is not the only way to refer to these types of buildings. Other synonyms include three-flat, triplex, and tri-level. These constructions are popular in urban areas as they are cost-effective, allowing multiple families to reside in a single building. While they may not be as common in other parts of the country, tripledeckers remain an enduring symbol of Boston architecture and the city's working-class heritage.