Cambridge, Mass., Zoning Ordinance art. 4.000, § 4.60 (2025) § 4.20

4.21 Accessory Uses .
a. An accessory use shall be permitted only on the same lot as the building or use to which it is accessory, with the following exceptions:
(1) Off street parking facilities complying with the requirements of Section 6.50 may be located on a separate lot;
(2) The Board of Zoning Appeal may grant a Special Permit for a use accessory to a scientific research, scientific development, or related production activity, whether or not on the same lot as such activity. A Special Permit shall be granted where said Board finds that the proposed accessory use does not substantially derogate from the public good.
(3) A use accessory to other permitted uses within the Cambridge Center MXD District may be located on other lots in the MXD District.
b. Providing nontransient lodging within a residential structure shall be considered an accessory use only if there is compliance with each of the following conditions:
(1) The residential structure is a single-family, semi-detached or two family dwelling;
(2) The owner of the building resides on the premises;
(3) Lodging is provided to not more than two roomers or boarders;
(4) Separate cooking facilities are not maintained for the roomers or boarders;
(5) No sign or nameplate for said roomers or boarders is displayed; and
(6) Signs advertising the availability of such lodging is not regularly displayed on the premises.
c. Provisions of garage or parking space for occupants, employees, customers, or visitors shall be considered as an accessory use.
d. The following Home Occupations and other Home Occupations, provided that they are accessory and incidental to the principal residential use, shall be considered accessory uses, provided also that only residential occupants of the dwelling unit are practicing or employed on the premises at any one time unless otherwise specified below, that all activities take place entirely within a building, and that no offensive noise, vibration, smoke, dust or other particulate matter, heat, humidity, glare, or other objectionable effects are produced:
(1) The office of a resident physician, dentist, attorney-at-law, architect, landscape architect, engineer, or member of another profession, in which case up to three persons may practice or be employed on the premises at any one time including persons who are not residential occupants but are employed to assist a primary practitioner residing on the premises;
(2) The salon of a properly licensed massage therapist;
(3) The studio of an artist, performing artist, craftsperson, graphic designer, photographer, or similar creative professional;
(4) A Retail Residential Kitchen permitted to produce Cottage Food Products, as regulated by 105 CMR 590.001(C), as it may be amended; and
(5) At a residence in a residential district, the care of a household pet that does not permanently reside at that residence, provided that only one such animal per day is kept on the premises.
e. In multifamily dwellings containing twenty-five or more dwelling units, hospitals or hotels with more than fifty sleeping rooms, a newsstand or other retail shop, a barber shop or similar service establishment, a dining room or other eating establishment shall be considered as an accessory use provided that (1) the establishment is primarily intended for occupants of the building, hotel or hospital; (2) the establishment is conducted entirely within and only entered from the interior of the dwelling, hospital or hotel; and (3) no signs or other advertising is visible from outside the building.
f. In an office building containing at least one hundred thousand (100,000) square feet of gross floor area, a newsstand, candy/tobacco stand, barbershop or other similar service establishment primarily intended for occupants of the building shall be a permitted accessory use provided that such activities are conducted and entered only from within the building and no signs or advertising devices thereof are visible from outside the building.
g. The area occupied by accessory uses shall be subject to the following limitations:
(1) The total area of uses accessory to the principal use may not occupy more than twenty-five (25) percent of the gross floor area of the building in which the principal use is located or twenty-five (25) percent of the area of the dwelling unit when the accessory use is located in a residence.
(2) The total area of uses or buildings accessory to the principal use except for parking facilities and driveways may not occupy more than fifteen (15) percent of the area of the lot.
(3) The area limitations of this paragraph 4.21 g shall be applicable in all zoning districts except the Cambridge Center MXD District; however, if explicitly stated elsewhere in this Ordinance certain accessory uses in specified districts may exceed the foregoing area limitation.
h. In Residence C-1 Districts an accessory building shall not be located nearer to any lot line than the minimum setback in the zoning district.
i. In a Residence District an accessory use shall not involve the maintenance of a stock in trade or the use of signs, illumination, show windows or displays either exterior or interior, except such signs as are permitted by Article 7.000 .
j. A dwelling or mobile home shall not be considered an accessory building except in an Industrial District for the accommodation of a night watchman or janitor or if it otherwise meets the definition of an Accessory Apartment.
k. An accessory building in Residence C-1, and Office-1 districts shall not exceed fifteen (15) feet in height above the ground level.
l. No accessory building may be converted to a residential use unless it conforms with the district dimensional regulations specified in Section 5.30 .
m. Limited manufacturing activity shall be considered an allowed accessory use to a technical research and development office, laboratory or research facility in a nonindustrial district provided that the following requirements are satisfied:
(1) Such manufacturing activity is related to research and development activities of the principal use.
(2) No manufacturing activity customarily occurs within fifty (50) feet of a residence or residential district.
(3) All manufacturing activity customarily occurs inside of buildings; however, outside research work and incidental outside fabrication of equipment to conduct outside experimentation shall be permitted.
(4) Outside research in nonindustrial districts should not customarily involve noxious activity which creates disturbances off of the premises.
(5) Manufacturing activity, excluding incidental fabrication of outside experiments, shall not occupy an area in excess of sixty (60) percent of the gross floor area of a building or group of associated buildings owned by the same establishment.
n. A helipad or airport shall not be considered as an accessory use.
o. Beekeeping, conducted in conformance with the Standards for Urban Agriculture set forth in Article 23.000 of this Zoning Ordinance and all other applicable laws, rules and regulations, shall be considered an allowed accessory use when conducted on the lot or and in conjunction with one of the following principal uses: residential (all uses listed in Section 4.31), transient accommodations (all uses listed in Section 4.31.1), institutional (all uses listed in Section 4.33), office and laboratory (all uses listed in Section 4.34), Convenience Store (Section 4.35.a-1), Merchandise Store (Section 4.35 a-2), Grocery Store (4.35 a-3), Craft Retail and Production Shop (Section 4.35 b), and light industry (all uses listed in Section 4.37).
p. Henkeeping, conducted in conformance with the Standards for Urban Agriculture set forth in Article 23.000 of this Zoning Ordinance and all other applicable laws, rules, and regulations, shall be considered an allowed accessory use when conducted on the lot of and in conjunction with one of the following principal uses: residential (Section 4.31 a.-h., excluding transient accommodations), any religious use (Section 4.33 a.), and any educational use (Section 4.33 b.).
4.22 Accessory Apartments shall be permitted in all zoning districts where Residences are permitted.
4.23 Offices in Residences . In a Residence C-2A, C-3, or C-3B district, offices for physicians and dentists may be located on the first or second floor of a residential building where such office space does not exceed ten (10) percent of the gross floor area of the building. In a Residence C-3A district, up to forty (40) percent of the gross floor area of a residential building may be devoted to business and professional offices, but not technical offices.
4.24 Temporary Buildings and Uses . The Superintendent of Buildings may grant a permit for a temporary building or use incidental to a building development, which does not comply with the provisions of this Ordinance, where reasonably required for such development. Such permit may be issued for an initial period of not more than one year, and in the case of a building, only upon application accompanied by a bond and bill of sale to the City, effective in case the building is not removed prior to the expiration of the permit. Permits may be renewed by the Superintendent of Buildings for successive periods of not more than one year each, not to exceed a total of three years.
4.25 Non Open Space Uses in Open Space Districts . The purpose of this section is to provide for public notification and review of governmental and institutional nonopen space development statutorily exempt from prohibition in designated Open Space Districts. All uses in an Open Space District other than a park or recreation use permitted by Subsection 4.33.f shall comply with the procedural requirements of this Subsection prior to the issuance of any building or special permit, variance or other approval or before conveyance of any lot within the district.
4.25.1 A report shall be submitted to the Planning Board and filed with the City Clerk by the agency or other party proposing such non open space development or proposing to convey a lot. This report shall include the following information, as appropriate:
(1) A map indicating the location and area of the land proposed for nonopen space development or for conveyance.
(2) A description of the proposed development and future use of the area including information concerning the proposed site plan, physical design, and user population.
(3) An analysis of alternative sites for the development outside of the district.
(4) Evaluation of the anticipated impacts of the development or property transfer on the remainder of the open space district, upon the ability of alternative park and recreation areas in the neighborhood and city to meet the needs served by the affected open space district which would be displaced by the proposed action, and upon other land uses in the neighborhood.
(5) Any other information reasonably determined pertinent by the Planning Board.
4.25.2 Within thirty (30) days of the receipt of a report required by Section 4.25.1, the Planning Board shall hold a public hearing concerning the proposed development or conveyance. Notice for the hearing shall comply with the requirements of Section 11, Chapter 40A, G.L.
4.25.3 The Planning Board shall prepare a report with recommendations concerning the proposed development or conveyance, including conditions that should be attached to such action. This report shall be filed with the City Clerk within thirty (30) days of the public hearing required in Section 4.25.2. Filing of such a report shall satisfy the requirements of this Section 4.25. Failure of the Board to file a report within thirty (30) days of the public hearing shall obviate any further actions under this Section 4.25.
4.26 [Deleted]
4.27 Special Use Limitations in the Business B-1 and B-2 Districts .
4.27.1 In the Business B-1 and B-2 districts, the uses specified in Subsection 4.35 shall be permitted provided that they occupy no more than twenty-five (25) percent of the maximum gross floor area allowed on the lot. However, the gross floor area of any single retail establishment shall not exceed twelve thousand (12,000) square feet.
4.27.2 In the Business B-1 district, the portion of any parcel within forty-five (45) feet of a front lot line facing Green Street shall be limited to the following uses: (1) residential uses permitted by Subsections 4.31 a, b, d, and g; (2) parking which is both covered and enclosed and which is accessory to dwelling units located within said aforementioned portion of the parcel; and (3) landscaped green space subject to the requirements of Subsection 4.27.3; however, where more than fifty (50) percent of the area of said portion of a lot is devoted to landscaped green space a special permit shall be secured from the Planning Board. Development plans for parcels which face Green Street shall show how such portion will be used in compliance with this Subsection 4.27.2. Completion of plans for said forty-five (45) foot portion shall be required prior to the issuance of a Certificate of Occupancy for development on other portions of the parcel. It is the intention of this Subsection 4.27.2 that the pattern of property ownership rights existing at the time of adoption of these regulations not be altered in a way to circumvent the creation of a residential or green space buffer next to Green Street. Therefore, for the purposes of this Subsection 4.27.2, a parcel shall consist of one or more lots as defined in Article 2.000 or parts of such lots which, at the time of the effective date of this Subsection 4.27.2 were either in the same ownership or which had some legal relationship to one another through purchase and sales agreements, purchase options, lease agreement, or options, or through some similar agreement or instrument.
4.27.3 Landscaped green space within the forty-five (45) foot portion of a lot described in Subsection 4.27.2 shall be open to the sky and shall be located at an elevation within five (5) feet of the grade level at the Green Street lot line. Such space shall include a minimum of one three inch caliper tree for each nine hundred (900) square feet of area within such landscaped portion. A suggested list of trees is contained in Section 11.16.4, under 4b. In addition to the criteria listed in Subsection 10.40 , the Planning Board shall evaluate special permit applications with respect to the following: continuity with other open spaces, relationship to other lots, and/or creative design features.
4.27.4 The Business B-1 and Business B-2 districts shall be considered areas of special planning concern. Development proposals listed in Subsection 11.42 shall be subject to the development consultation procedures specified in Article 19.000 .
4.28 Art/Craft Studio . The purpose of this Section 4.28 is to ensure that art/craft studios located in Residence C and Office Districts will be compatible with other permitted uses, particularly in residential neighborhoods.
4.28.1 The Board of Zoning Appeal may grant a special permit for the location of an art/craft studio or group of studios in Residence C-1, C-2, C-2A, C-2B, C-3, C-3A, C-3B and Office Districts provided that the following requirements are satisfied;
a. Residence C-1, C-2, C-2A, C-2B, C-3, C-3A, C-3B Districts:
1. The studio shall be located in a principal use nonresidential building in existence as of May 1, 1984. Structures or buildings accessory to residential uses shall not be so used.
2. The required amount of parking in Article 6.000 may be reduced only if the Board determines that a lesser amount of parking will not cause excessive congestion, endanger public safety, substantially reduce parking availability for other uses or otherwise adversely impact the neighborhood.
b. Residence C-1, C-2A, C-2B, C-3, C-3A, C-3B and Office Districts:
1. The studio will be principally used as a studio for independent artists and crafts people in the creation of their own work. Mass production and assembly line techniques are prohibited.
2. The type of studio use shall be appropriate to the particular building and its location:
a. the building shall be structurally sound.
b. the proposed studio use will not generate traffic in volume or type in excess of that normally occurring in the adjacent neighborhood.
c. no bulk storage of toxic or highly flammable materials shall occur.
d. the proposed studio use shall satisfy all applicable building, fire safety, and health codes.
e. noise shall be restricted to levels customarily permitted in the districts as regulated in General Ordinance #887 "Regulations for the Control of Noise," or as customarily produced by other permitted uses in the district, whichever is less.
f. noxious odors, dust, and/or fumes shall be effectively disposed of and confined to the premises to avoid air pollution and nuisance to the adjacent neighborhood.
3. All activity must be carried out within the building, including the storage of materials.
4. No more than three (3) persons shall practice or be employed at one time per studio.
5. There shall be no retail sales except as may occur as an activity incidental to exhibition permitted in b(6) below:
6. Public exhibitions shall not be permitted except as specifically authorized in the special permit. The number and duration of any such exhibitions shall be specifically stated, shall be for arts/crafts created on the premises, and shall only be permitted upon finding that the residential or other prevailing neighborhood character will not be significantly, negatively affected.
4.28.2 In issuing a special permit under this Section 4.28 the Board of Zoning Appeal shall state the specific arts and crafts uses or range of uses being authorized for each studio granted a permit.
4.28.3 Nothing in this Section 4.28 shall prohibit the establishment of residential uses, permitted in the district, subsequent to the issuance of a special permit under this Section 4.28. The establishment of residential uses shall not alter the principal use nonresidential status of the building for the purpose of continuing or future authorizations for art/craft studios under provisions of this Section 4.28
4.29 Conversion of Non Residential Structures to Residential Use . Where it is proposed to convert an existing principal-use structure designed and built for non residential use to residential uses or to certain non-residential uses not otherwise allowed in the applicable zoning district as set forth in the following Section 4.30 - Table of Use Regulations, such uses may be allowed after issuance of a special permit by the Planning Board consistent with the provisions of Section 5.28.2.
4.210 Combined Retail or Consumer Service Uses.
(a) A permitted Retail or Consumer Service Establishment may combine the functions of two or more principal uses that are permitted in the district.
(b) The following principal uses, if not otherwise permitted in the district, shall be permitted as additional allowed principal uses if combined with another permitted principal non-residential use, subject to the limitations below:
(1) Sales. The display and sale of goods that are directly related to the operation of the other principal use at the property and are intended for sale to occupants, patrons, or visitors of the other principal use, including but not limited to supplies that are utilized in the operation of the other principal use or promotional materials for the other principal use.
(2) Programs and Services. On-site activities including but not limited to minor repairs, instructional classes, presentations, workshops, consultations, or similar programs and services provided to occupants, patrons, or visitors of the other principal use.
(3) Food and Beverage Service. The provision of meals, snacks, beverages, and other food products prepared on-site or off-site and intended for consumption on-site by occupants, patrons, or visitors of the other principal use.
(4) Entertainment and Recreation. The provision of activities including but not limited to live or recorded music, video entertainment, other live performances, group games or contests, or other entertainment or recreational activities for the enjoyment of occupants, patrons, or visitors of the other principal use.
Limitations: (i)
The additional use may occupy no more than 25% of the total Gross Floor Area of the other principal use, or must be limited in duration to no more than 25% of the total hours of operation of the other principal use on a weekly basis.
(ii) No additional parking or loading facilities shall be required or provided for the additional use (additional bicycle parking may be provided but shall not be required).
(iii) Signage requirements set forth in Article 7.000 of this Zoning Ordinance shall be calculated for the establishment as a whole rather than individually for each component use.
(iv) All uses shall conform to all applicable licensing requirements and all other laws, codes, and regulations.