Section 2. As used in this chapter, the following words shall have the following meanings:
''Affordable housing'', housing affordable to and occupied by individuals and families whose annual income is less than 80 per cent of the areawide median income as determined by the United States Department of Housing and Urban Development. Affordability shall be assured for a period of not less than 30 years through the use of an affordable housing restriction as defined in section 31 of chapter 184.
''Approved smart growth zoning district'', a smart growth zoning district that has been adopted by a city or town and approved by the department in accordance with this chapter and the regulations of the department, so as to be eligible for the receipt of financial and other incentives. The department may revoke its approval if the obligations of the city or town are not met.
''Approving authority'', a unit of municipal government designated by the city or town to review projects and issue approvals under section 11.
''Comprehensive housing plan'', a plan to be prepared by each city or town that provides an assessment of the housing needs within a city or town and describes specific strategies to address these needs, in accordance with regulations of the department.
''Density bonus payment'', a one-time payment to a municipality from the trust fund, established in section 35AA of chapter 10 for each housing unit of new construction that is created in a smart growth zoning district.
''Department'', the department of housing and community development.
''Developable land area'', that area within an approved smart growth zoning district that can be feasibly developed into residential or mixed use development determined in accordance with regulations of the department. Developable land area shall not include: (1) land area that is already substantially developed, including existing parks and dedicated, perpetual open space within such substantially developed portion; (2) open space designated by the city or town as provided in section 6; or (3) areas exceeding 1/2 acre of contiguous land that are unsuitable for development because of topographic features or for environmental reasons, such as wetlands.
It shall include the land area occupied by or associated with underutilized residential, commercial, industrial or institutional buildings or uses that have the potential to be recycled or converted into residential or mixed use developments as determined in accordance with regulations of the department.
''Eligible locations'', (1) areas near transit stations, including rapid transit, commuter rail and bus and ferry terminals; (2) areas of concentrated development, including town and city centers, other existing commercial districts in cities and towns, and existing rural village districts; or (3) areas that by virtue of their infrastructure, transportation access, existing underutilized facilities, and/or location make highly suitable locations for residential or mixed use smart growth zoning districts.
''Historic district'', a district in a city or town characterized by the unique historic quality of the buildings within the district, and in which exterior changes to all buildings and the construction of new buildings are subject to special architectural and design guidelines as voted by the city or town pursuant to state law.
''Letter of eligibility'', a letter to a city or town to be issued by the department within 60 days of receiving a complete and approvable application from a city or town for approval of a smart growth zoning district.
''Mixed use development'', a development containing a mix of some or all of multi-family residential, single-family residential, commercial, institutional, industrial and other uses, all conceived, planned and integrated to create vibrant, workable, livable and attractive neighborhoods.
''Multi-family housing'', apartment or condominium units in buildings which contain or will contain more than 3 such units.
''New construction'', construction of new housing units, the substantial rehabilitation of existing buildings or the conversion to residential use of existing buildings to create additional housing units, to the extent those units could not have been constructed or converted under the underlying zoning.
''Open space'', shall include, but not be limited to, land to protect existing and future well fields, aquifers, and recharge areas, watershed land, agricultural land, grasslands, fields, forest land, fresh and salt water marshes and other wetlands, ocean, river, stream, lake and pond frontage, beaches, dunes, and other coastal lands, lands to protect scenic vistas, land for wildlife or nature preserve and land for recreational use.
''Project'', a proposed residential or mixed-use development within a smart growth zoning district.
''Smart growth zoning district'', a zoning district adopted by a city or town under this chapter that is superimposed over 1 or more zoning districts in an eligible location, within which a developer may elect to either develop a project in accordance with requirements of the smart growth zoning district ordinance or by-law, or develop a project in accordance with requirements of the underlying zoning district.
''Smart growth zoning district certificate of compliance'', a written certification by the department in accordance with section 7.
''Trust fund'', the Smart Growth Housing Trust Fund, established by section 35AA of chapter 10.