4.1.1. 
Conformance Required. No building or structure shall be built, nor shall any existing building or structure be enlarged, except in conformance with the regulations of the bylaw as to lot coverage, lot area per dwelling unit, lot width, front, side and rear yards, and maximum height of structures, in the districts as set forth below except as may otherwise be provided elsewhere in the bylaw.
4.1.2. 
Table of Dimensional and Density Regulations. All buildings and structures shall comply with the Table of Dimensional and Density Regulations set forth below.
[Amended 10-15-2018 ATM by Art. 10; 10-21-2019 ATM by Art. 7]
Table of Dimensional and Density Regulations
District
Lot Area Required
Lot Frontage Required
Permitted Lot Coverage
Required Setback Distance from Street Center Line
Required Front Yard Depth
Required Side Yard Width
Required Rear Yard Depth
Single Residence A
15,000 sq. ft.
110 ft.
35%
50 ft.
30 ft.
15 ft.
20 ft.
Single Residence B
30,000 sq. ft.
150 ft.
35%
60 ft.
40 ft.
20 ft.
20 ft.
Single Residence C
40,000 sq. ft.
180 ft.
35%
60 ft.
40 ft.
25 ft.
20 ft.
Single Residence D
60,000 sq. ft.
210 ft.
35%
60 ft.
40 ft.
30 ft.
20 ft.
Limited Business
35%
60 ft.
40 ft.
15 ft. for dwellings
20 ft. for dwellings
General Business
50%
60 ft.
40 ft.
15 ft.1
20 ft. for all other buildings
Commercial
50%
60 ft.
40 ft.
15 ft.1
20 ft. for all other buildings
Limited Industrial
3 acres
300 ft.4
30%
100 ft.
100 ft.
100 ft.2
40 ft.
Elderly Housing District
4 acres
200 ft.
25%
70 ft.
50 ft.
25 ft.
30 ft.
Office Park District
3 acres
200 ft.3
30%
75 ft.
50 ft.
50 ft.
50 ft.
NOTES:
1
For other buildings, unless having a party wall on the same lot line.
2
Where the lot line forms the side boundary of a Single Residence A, B, C, or D District, or 100 feet from such a boundary where not co-incident with the lot line; otherwise 40 feet.
3
On a public way or 50 feet on a private way or right-of-way that:
(1)
Has been determined to be adequate and appropriate for access by the Planning Board;
(2)
Has been constructed in accordance with the Planning Board Regulations then applicable to construction of public ways;
(3)
Has been specifically designed for office park use; and
(4)
Will be privately maintained by the owner of the office park site.
4
In a Limited Industrial District, where the way is shown as an industrial service street on a definitive subdivision plan duly approved by the Lynnfield Planning Board, the frontage need not exceed 50 feet.
4.1.3. 
Building Heights. In all districts, no building shall be constructed to exceed more than three stories or 40 feet in height, the height in each case to be measured vertically from the average finished grade of the ground adjoining such building to the highest point of the roof for flat roofs, to the deck line for mansard roofs, and to the average height between eaves and ridge for gable, hip and gambrel roofs. Provided, however, in a Commercial District and in a Limited Industrial District, the height of a building may exceed 40 feet by one foot for each additional foot by which:
[Added 10-15-2018 ATM by Art. 10]
1. 
The front yard depth exceeds the depth herein required, or
2. 
The narrower side yard exceeds the side yard width herein required, or
3. 
The rear yard exceeds the rear yard depth herein required, whichever of the three additional distances is the smallest.
A building thus permitted to exceed 40 feet in height may be constructed to contain more than three stories, but no such building shall in any case have a height greater than 50 feet.
Chimneys, spires, towers, and other projections not used for human occupancy, whether constituting separate structures or attached to buildings, may be constructed above the height limitations herein before established, but no such structure or projection shall be constructed in any district to a height greater than 50 feet without authorization of the Board of Appeals.
Lot side lines shall not vary more than 20° from being perpendicular to the street boundary, or a tangent thereto, for a distance of at least 30% of the district frontage requirement. The same shall apply to the intersection of side lot lines with the rear boundary.
[Amended 10-21-2019 ATM by Art. 7]
In Single Residence Districts A, B, C, and D, and in tracts of land which otherwise qualify for Green Belt residential development under the bylaw, land which lies within a Flood Plain District or a Wetland as defined in MGL c. 131, § 40, as amended, shall not be used to meet the minimum area required for lots in each of such districts; provided however, that nothing contained in this section shall prevent such land from being used for such purpose in Elderly Housing Districts.
In the Elderly Housing District, the lot frontage required may be met upon a way situated within an adjoining 40R District (i.e., an overlay district adopted by the Town pursuant to General Laws, Chapter 40R),[1] provided that:
1. 
The lot in the Elderly Housing District has vested rights in said way over the entire frontage and to a public way, for all purposes for which ways may be used in the Town of Lynnfield and for the installation of utilities;
2. 
The way has been approved by the Planning Board as part of a plan approval for a development project within said 40R District; and
3. 
The way will be privately maintained by the owner of such development project within said 40R District.
[1]
Editor's Note: See MGL c. 40R, § 1 et seq.
[Amended 10-21-2019 ATM by Art. 7]
In all districts, except as herein provided, no dwelling shall be constructed on a lot having a width at any point between the frontage way and that part of the dwelling nearest thereto of less than 80% of the frontage distance required for the district in which said lot is located. The required lot width shall be measured parallel to the line along which the required frontage is to be measured, as hereinbefore specified. Any lot shown on a plan duly recorded or registered on or before March 12, 1962, and any dwelling then existing or thereafter built thereon, shall be exempt from the lot width requirement.
No open display or other open use, where permitted, and no sign or other structure, shall be located nearer to the exterior line of any public or private way than 30 feet in a Limited Business, General Business or Commercial District, or 80 feet in a Limited Industrial or Office Park District, except the following:
1. 
Utility pole or mail box.
2. 
Plants growing in the soil, if not obstructing the view of cars entering and leaving the premises.
3. 
Parking lot for passenger automobiles.
4. 
Sign attached to a building if extending not more than three feet in front of said building, and only above a height of 10 feet.
In all districts except Elderly Housing Districts, no building need be farther from either the exterior or the center line of any public or private way than the average distance from each such line, respectively, of the dwellings or other principal buildings located on the adjoining side lots. In determining such average, a vacant side lot shall be considered as though occupied by a building having the required setback and front yard. The side yard and rear yard requirements hereof may be varied by the Board of Appeals in the specific case of an irregular, narrow, or shallow lot or a lot unusual either in shape or topography, provided that the spirit and intent of the bylaw with regard to yards and other open spaces is preserved.
4.8.1. 
Cornices or Eaves. Nothing herein shall prevent the projection of cornices or eaves not exceeding 18 inches in width, or of uncovered steps, or window sills into any required yard or other open space.
4.8.2. 
Shed. In all residence districts, no private tool shed used exclusively by the occupants of the residence located on the lot on which the shed is located need be farther from the side line of said lot than 10 feet nor farther from the rear line of said lot than five feet, provided that said tool shed has a floor area of no more than 150 square feet and a height of no more than 12 feet.
No lot on which a building is located in any district shall be reduced or changed in size or shape so that the building or lot fails to comply with the lot area, frontage, width, coverage, setback or yard provisions of this section, without the approval of the Board of Appeals. This prohibition shall not apply, however, when a portion of a lot is taken or conveyed for a public purpose.
[Added 10-21-2019 ATM by Art. 7]
In all Single Residence Districts, except as herein provided, no dwelling shall be constructed on a lot having less area than the "Lot Area Required," or having less frontage on a public or private way to which said lot has actual physical and legal access, than the "Lot Frontage Required" specified in the Table in § 4.1.2.
[Added 10-21-2019 ATM by Art. 7]
In all districts, no building shall be constructed to cover, together with all other buildings on the lot, a larger portion of the lot area than the "Permitted Lot Coverage" specified in the Table of Dimensional and Density Regulations in § 4.1.2.