Starting in the early 1980s, however, they became desirable again as older streetcar suburbs began to gentrify, often by buyers looking for homes where they could live in one unit and rent the other two, thus helping them pay their mortgage. As condominiums became more common, many were converted into individually-owned units. Since 1990, many three-deckers in Worcester, Massachusetts, have been listed on the National Register of Historic Places. Recently, a new wave of three-decker apartment houses has been built in areas of Boston as an alternative to the townhouse style condominium or apartment buildings more typically associated with suburban areas. Boston's zoning regulations allow new three-family houses to be constructed in areas with existing three-deckers. However, building codes for the new buildings are far more stringent today, with requirements for fire sprinkler systems and handicap access. See also List of house types List of Registered Historic Places in Worcester, Massachusetts Polish flat Affordable housing References External links Worcester Historical Museum Sightseeking, 2005 Worcester's three-deckers New England