Mass. Gen. Laws ch. 40A § 1A
As used in this chapter the following words shall have the following meanings:
"Accessory dwelling unit", a self-contained housing unit, inclusive of sleeping, cooking and sanitary facilities on the same lot as a principal dwelling, subject to otherwise applicable dimensional and parking requirements, that:
"As of right", development that may proceed under a zoning ordinance or by-law without the need for a special permit, variance, zoning amendment, waiver or other discretionary zoning approval.
"Eligible locations", areas that by virtue of their infrastructure, transportation access, existing underutilized facilities or location make highly suitable locations for residential or mixed use smart growth zoning districts or starter home zoning districts, including without limitation:
"Gross density", a units-per-acre density measurement that includes land occupied by public rights-of-way and any recreational, civic, commercial and other nonresidential uses.
"Lot", an area of land with definite boundaries that is used or available for use as the site of a building or buildings.
"MBTA community", a city or town that is:
"Mixed-use development", development containing a mix of residential uses and non-residential uses, including, without limitation, commercial, institutional, industrial or other uses;
"Multi-family housing", a building with 3 or more residential dwelling units or 2 or more buildings on the same lot with more than 1 residential dwelling unit in each building.
"Natural resource protection zoning", zoning ordinances or by-laws enacted principally to protect natural resources by promoting compact patterns of development and concentrating development within a portion of a parcel of land so that a significant majority of the land remains permanently undeveloped and available for agriculture, forestry, recreation, watershed management, carbon sequestration, wildlife habitat or other natural resource values.
"Open space residential development", a residential development in which the buildings and accessory uses are clustered together into 1 or more groups separated from adjacent property and other groups within the development by intervening open land. An open space residential development shall be permitted only on a plot of land of such minimum size as a zoning ordinance or by-law may specify which is divided into building lots with dimensional control, density and use restrictions for such building lots varying from those otherwise permitted by the ordinance or by-law and open land. The open land may be situated to promote and protect maximum solar access within the development. The open land shall either be conveyed to the city or town and accepted by said city or town for park or open space use, or be made subject to a recorded use restriction enforceable by said city or town or a non-profit organization the principal purpose of which is the conservation of open space, providing that such land shall be kept in an open or natural state and not be built for residential use or developed for accessory uses such as parking or roadway.
"Permit granting authority", the board of appeals or zoning administrator.
"Solar access", the access of a solar energy system to direct sunlight.
"Solar energy system", a device or structural design feature, a substantial purpose of which is to provide daylight for interior lighting or provide for the collection, storage and distribution of solar energy for space heating or cooling, electricity generating, or water heating.
"Special permit granting authority", shall include the board of selectmen, city council, board of appeals, planning board, or zoning administrators as designated by zoning ordinance or by-law for the issuance of special permits.
"Transfer of development rights", the regulatory procedure whereby the owner of a parcel may convey development rights, extinguishing those rights on the first parcel, and where the owner of another parcel may obtain and exercise those rights in addition to the development rights already existing on that second parcel.
"Transfer of development rights zoning" or "TDR zoning", zoning that authorizes transfer of development rights by permitting landowners in specific preservation areas identified as sending areas to sell their development rights to landowners in specific development districts identified as receiving areas.
"Zoning", ordinances and by-laws, adopted by cities and towns to regulate the use of land, buildings and structures to the full extent of the independent constitutional powers of cities and towns to protect the health, safety and general welfare of their present and future inhabitants.
"Zoning administrator", a person designated by the board of appeals pursuant to section thirteen to assume certain duties of said board.
Mass. Gen. Laws ch. 40A, § 40A:1A