Cohasset City Zoning Code
ARTICLE 5
Dimensional Regulations
§ 300-5.1 General.
A.
No new building or other structure may be erected, and no new lot may be created or developed, except in conformity with the applicable dimensional requirements set forth in this Article 5 or as may be expressly provided elsewhere in this Zoning Bylaw.
B.
No existing lot on which a building is located may be reduced or changed in size or shape, nor may the building be moved or changed so that either the building or lot fails to comply with the dimensional requirements, or other provisions of this Zoning Bylaw, applicable to said lot or to the construction of such building on said lot, except:
§ 300-5.2 Interpretation.
[Amended 12-9-2024 STM by Art. 16]
The basic dimensional requirements pertaining to development and use of land and structures in each zoning district are set forth in the § 300-5.3, Table of Dimensional Regulations. For purposes of interpreting said dimensional requirements, the following rules will apply:
A.
Lot area. The calculation of minimum lot area may not include any land within the limits of an abutting street or private way, or any portion of the lot below mean high water.
B.
Lot frontage. Minimum lot frontage is measured along a continuous length of the street line. On corner and through lots, minimum frontage is measured along one street line only.
C.
Lot width.
(1)
The required minimum lot width specified in the § 300-5.3 Table of Dimensional Regulations is measured between the sidelines of the lot, along a line which is parallel to the center line of the abutting street and touches the point of the principal building nearest to the front lot line, which measurement line may or may not coincide with the required front setback line.
D.
Setbacks.
(1)
Front, side, and rear yard setbacks must conform to the yard definitions set forth in Article 2 of this Zoning Bylaw.
(2)
The minimum required front yard setback for a building is measured from the front lot line and extends the full width of the lot between the side lot lines; provided, however, that where a street has a right-of-way width of less than 40 feet, the setback distance shall include an additional 20 feet and be measured from the center line of the street, and further provided that any setback and/or front, side, or rear yard shall conform to the yard definitions as set forth within Article 2.
(3)
For the purpose of determining front yard setback requirements, all yards bounding on a street, including but not limited to through lots and corner lots, will be considered front yards.
(4)
When measuring the setback distance between a building and a property line, the following permitted building projections shall be disregarded:
(a)
Construction elements that extend no more than two feet from the building wall surface, including but not limited to eaves, chimneys, bay windows that do not provide additional floor area, and belt courses; and
(b)
Unenclosed entry porches, unenclosed steps, and bulkheads, provided that they do not exceed 30 square feet in area, and do not project more than six feet from the foundation wall of the building.
E.
Lot coverage. The lot area measurement used to calculate lot coverage by buildings and other impervious surfaces may not include more than 50% of any wetlands, water bodies, and land with slopes greater than 45% within the lot boundaries.
§ 300-5.3 Table of Dimensional Regulations.
[Amended 12-9-2024 STM by Art. 17]
Table of Dimensional Regulations | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
District | Min. Lot Area (square feet) | Min. Lot Frontage (feet) | Min. Lot Width (feet) | Min. Setbacks (feet) | Max. Height (feet) | Max. % Lot Coverage | ||||
Front | Side | Rear | Principal | Accessory1 | Total | By Buildings | ||||
R-A | 18,0002 | 50 | 100 | 20 | 153 | 154 | 35 | 25 | 30 | 205 |
R-B | 35,0006 | 50 | 125 | 30 | 207 | 208 | 35 | 25 | 30 | 20R- |
R-C | 60,0009 | 50 | 150 | 30 | 2010 | 3011 | 35 | 25 | 30 | 20 |
HAR | — | 20 | 20 | 15 | 10 | 15 | 35 | 25 | 80 | — |
VIL | 5,000 | 50 | 50 | 15 | 10 | 15 | 35 | 25 | 80 | — |
3A-C | 10,00013 | 5014 | 10015 | 5016 | 2017 | 2018 | 35 | 25 | 60 | 2519 |
OS | — | — | — | 30 | 20 | 30 | 35 | 25 | — | 25 |
NOTES: | |
|---|---|
1 | Except where the Zoning Bylaw otherwise expressly limits the heights of certain accessory structures such as, but not limited to, signs, fences, solar energy installations, or communication structures. |
2 | Plus 6,000 square feet for each additional dwelling unit created in a two-family conversion or a multifamily conversion. |
3 | Except 10 feet for any portion of a principal building with less than 15 feet in height, and three feet for any accessory building with less than 15 feet in height and set back at least 75 feet from the front lot line. |
4 | Except three feet for any accessory building with less than 15 feet in height and set back setback of at least 75 feet from the front lot line. |
5 | Except the lesser of 25% of the lot area or 3,600 square feet for a lawfully preexisting nonconforming lot containing less than 18,000 square feet of area. |
6 | 48,000 square feet for a two-family conversion; 48,000 square feet for the first two dwelling units in a multifamily conversion plus 8,000 square feet for each additional dwelling unit. |
7 | Except 15 feet for any portion of a principal building with less than 15 feet in height, and six feet for any accessory building with less than 15 feet in height and set back at least 100 feet from the front lot line. |
8 | Except six feet for any accessory building with less than 15 feet in height and set back at least 100 feet from the front lot line. |
9 | 80,000 square feet for a two-family conversion; 80,000 square feet for the first two dwelling units in a multifamily conversion plus 10,000 square feet for each additional dwelling unit. |
10 | Except 15 feet for any portion of a principal building with less than 15 feet in height, and six feet for any accessory building with less than 15 feet in height and set back at least 100 feet from the front lot line. |
11 | Except six feet for any accessory building with less than 15 feet in height and set back at least 100 feet from the front lot line. |
12 | Except where the Zoning Bylaw otherwise expressly limits the height of certain accessory structures such as, but not limited to, signs, fences, solar energy installations, or communication structures. |
13 | 88,000 square feet for any dwelling containing two dwelling units, plus 4,000 square feet for each additional dwelling unit. |
14 | 200 feet for any dwelling containing two or more dwelling units. |
15 | 200 feet for any dwelling containing two or more dwelling units. |
16 | 15 feet for an accessory freestanding sign; 100 feet for any dwelling containing two or more dwelling units. |
17 | 50 feet for any dwelling containing two or more dwelling units. |
18 | 50 feet for any dwelling containing two or more dwelling units. |
19 | No maximum building coverage if the lot is used for a dwelling containing two or more dwelling units. |
Dimensional Limits in the 3A Multi-Family Overlay District | |
|---|---|
Maximum Density | 15 units per acre |
Minimum Frontage | 75 ft. |
Minimum Green Strip where project abuts Rte. 3A | 25 ft. |
Minimum Primary Structure Front Setback | 50 ft. |
Minimum Primary Structure Side & Rear Setbacks | 25 ft. |
Minimum Accessory Structure Front Setback | 75 ft. |
Minimum Accessory Structure Side & Rear Setbacks | 10 ft. 15 ft. if > 15 ft. high |
Maximum Height | 35 ft. or 3 stories |
Maximum Lot Clearing | 80% |
Maximum Coverage - Hardscape + Primary Structure | 70% |
Maximum Floor Area Ratio | 1.3 |
§ 300-5.4 Supplemental regulations.
[Amended 6-3-2024 ATM by Art. 18; 6-3-2024 ATM by Art. 22]
The following regulations supplement the basic dimensional requirements set forth in the § 300-5.3 Table of Dimensional Regulations.
A.
The maximum gross floor area of any single story in any building is 80,000 square feet.
B.
No open storage or display of goods, products, materials, or equipment, no gasoline pump, vending machine, or similar commercial device, and no other structure except as permitted under § 300-5.4D may be located nearer to any side or rear lot line than the required setback distance for a building on the lot, or 15 feet, whichever is less.
D.
Subject to the clear vision requirements for corner lots set forth in § 300-5.4E, the following structures may be located within a required side, rear or front yard, subject to the clear vision safety requirement for corner lots set forth in:
E.
A fence, hedge, wall, or similar enclosing structure located within a front yard of a corner lot may be no higher than three feet above the grade of the center lines of the abutting streets at any point within the clear vision safety triangle formed by a straight line across the lot which connects the two street lines at points measured 25 feet from the point of intersection of said street lines.
F.
For buildings and other structures in a VIL or HAR District, the required ten-foot side yard setback will not apply where the wall adjoining a side lot line is a party wall.
G.
The Zoning Board of Appeals may grant a special permit to allow a reduction in the minimum side yard setback requirements specified in the Table of Dimensional Regulations for the VIL and HAR Districts.
H.
The Planning Board may grant a special permit to allow a reduction in the minimum side, front or rear yard setback requirements specified in the Table of Dimensional Regulations for the VIL District.
I.
Minimum side yard requirements will not apply in the VIL District where the side lot line abuts a railroad right-of-way. The minimum rear yard requirements will not apply in the 3A-C District where the rear lot line abuts a railroad right-of-way.
J.
In any district except the 3A-C District, as an alternative to the minimum front setback requirements specified in the Table of Dimensional Regulations, a building may be set back from the street line a distance equal to the average setbacks of the principal buildings located within 200 feet on either side the building in question. If no principal building is located within said 200 feet, the intervening space will be counted as a building meeting the minimum front setback specified in the table (whether or not said space is laid out as a separate lot).
K.
Within the 3A-C District, no building or other structure may be built within 100 feet of a residence district boundary, except where the district boundary is a street, in which case the required distance will be reduced to 50 feet.
L.
In the VIL District, no new building may be located closer than 30 feet to any R-A or R-B District boundary, provided that where a lot is located only partially within the VIL District, this requirement will be satisfied if all new buildings on the lot are located at least 30 feet from any property boundary line which abuts an R-A or R-B zoned lot.
M.
Within the 3A-C District, a green strip not less than 35 feet wide must be maintained along the street frontage of any developed lot. Such green strip must be landscaped with grass, trees and/or shrubs. No paved areas except driveways, and no structures except permitted signs, are allowed within the required green strip.
N.
Within the 3A-C District, a green strip not less than 30 feet wide must be maintained along any property line abutting land residentially zoned land. The green strip may not be built upon or used for any purpose other than to serve as a vegetative buffer on which grass, bushes, flowers, or trees are grown and maintained. No structures or pavement are allowed within the required green strip.
O.
In the VB District, the municipal parking lot shown on the Assessor's Map as Parcels 18-004 and 18-014 may be used to satisfy the minimum lot frontage requirements specified in the Table of Dimensional Regulations, provided that the length of the property line bounding on the municipal parking lot is at least equal to the minimum frontage length specified in the table.
P.
Notwithstanding the height limitations set forth in the Table of Dimensional Regulations, the Zoning Board of Appeals may grant a special permit to allow light poles and lighting facilities to be erected to a height of 70 feet in the HB and LI Districts, for the sole purpose of illuminating athletic fields for night sporting events.
Q.
Landfill height limit. The vertical distance above the mean level of the ground within 10 feet of the horizontal limit of a landfill to the top surface of the landfill, including any final cap or covering material, may not exceed 45 feet.
R.
The minimum width of a legal service driveway is 12 feet.
S.
In the VIL and Harbor Districts, the following special height and setback restrictions will apply to buildings and other structures built within 25 feet of any residence district boundary other than a boundary formed by a street:
(1)
No portion of a principal building or structure built within said 25 feet may exceed 28 feet in height, and no portion of an accessory building or other structure built within said 25-foot distance may exceed 10 feet in height.
(2)
No portion of a building or structure may be built within 15 feet of a side or rear lot line abutting a residence district boundary.
§ 300-5.5 Large house plan review.
A.
Applicability.
i)
Unless the Building Inspector is in receipt of a written statement from the Planning Board that it has reviewed and approved an application for large house review in accordance with the provisions of this section, no building permit may issue for i) new construction of a single-family detached dwelling or building accessory to such a dwelling, or ii) any exterior alteration, expansion, reconstruction, or replacement of an existing single-family detached dwelling or building accessory to such dwelling, if the resulting residential gross floor area (RGFA) on the lot will exceed the greater of 4,000 square feet or an RGFA equal to 10% of the area of a lot.
B.
Application requirements.
(1)
A person applying for a large house plan review must file an application with the Planning Board, together with the filing fee, the RGFA calculation certified by a registered architect or engineer, and the following plans and documentation:
(a)
A site plan showing the location of the subject house, and the existing and proposed site conditions, topography, building elevations, setbacks, lot coverages, floor area ratios, grading, and landscape design;
(b)
For an existing house, photographs of all sides, and for both existing and proposed houses, a drawn or computer-generated depiction of how the house is proposed to appear post-construction, including exterior materials;
(c)
A context map with a narrative description of the surrounding neighborhood with data regarding house styles, sizes, dimensions, building siding materials, and context photographs of all within a 300-foot radius of the proposed house location.
(d)
Not less than two permanent survey monuments must be located on the property in question and shown on the plan, unless waived by the Planning Board.
(2)
The application, supporting plans, and documentation must address the design standards described in § 300-5.5C and must include such further information as the Planning Board may require.
(3)
For any subsequent applications concerning the same subject premises, the Planning Board may waive the filing of plans and documents to the extent they duplicate those previously filed.
C.
Planning Board review. An important purpose of the large house plan review process is to provide an opportunity for the Planning Board to discuss large house plan with the applicant and the abutters, toward the objective of making the proposed plan harmonious with, rather than harmful, injurious or objectionable to, existing properties and uses in the area.
(1)
Among the factors the Planning Board will consider in reviewing a proposed project is the degree to which the proposed construction conforms to following design standards:
(a)
Scale of buildings. The scale of the proposed construction should be appropriate in relation to the scale of other buildings in its vicinity. The construction plans should employ appropriate massing, screening, lighting, building and siding materials and other architectural techniques such as variation in detail, form and siting. The plans should address the need for vegetated buffers or screening, and the arrangement of structures to minimize casting shadows onto abutting property.
(b)
Preservation of landscape. The construction plan should minimize soil removal, as well as changes to wetlands, floodplains, hilltops, existing grades and existing vegetation on the site, and should preserve unique natural areas, topographic features such as ledge outcrops, significant trees and landscaping, and historic features.
(c)
Lighting. Exterior lighting should be limited to only that necessary to accomplish safety and design objectives and must be arranged to minimize the impact on neighboring properties.
(d)
Circulation. Walkways, drives and parking must be designed be safe and convenient and, insofar as practicable, should be designed and located in a manner that will not have adverse effects on the use and enjoyment of adjacent properties or on any Town streets abutting the premises.
(2)
In addition to the above design standards, the Planning Board may consider other factors based on previous reviews and decisions, on recommendations received from other Town boards or agencies, and by the requirements of other permits that have already issued or that may be required for the proposed construction.
D.
Procedure.
(1)
The Planning Board shall hold a hearing within 35 days of the filing of an application for a large house plan review.
(2)
The Planning Board shall, within one week of receipt of the application, transmit copies of the application and supporting materials to appropriate Town boards and departments for review.
(3)
The Planning Board shall give notice of such hearing to the applicant and to all owners of abutting lots in the manner called for in the Planning Board rules and regulations.
(4)
Within 14 days after the conclusion of the public hearing, the Planning Board shall either approve the application or approve the application with conditions and send a written statement of this final decision to the applicant and to the owners of abutting lots by regular mail. The Planning Board shall also transmit a copy of the final decision to the Building Inspector.
E.
Post approval. Any building, reconstruction or expansion following the Planning Board's approval of a large house plan must conform with any conditions in the statement of approval, and in all other respects with the application, plan, supporting documents and other representations of the applicant.
F.
Any changes or design deviations from the reviewed project must be resubmitted to the Planning Board for a subsequent, additional review unless determined by the Building Inspector to be minor or insubstantial in nature.
§ 300-5.6 Temporary structures.
In any business district, the Zoning Board of Appeals may grant a special permit to authorize the erection and maintenance of a temporary building or structure that does not conform to the requirements of this Zoning Bylaw, provided the Board finds that the temporary structure will not be detrimental or injurious to persons, property or improvements in the neighborhood or the Town. Such authorization may not be for more than one year and may not be extended.