4.1.1
Applicability. Each use, building, or structure must comply with
the standards described in Table 2, Schedule of Dimensional Controls,[1] except where provided otherwise by this bylaw.
[1]
Editor's Note: Table 2 is included as an attachment to this chapter.
4.1.2
Lots in More Than One District. When a lot is divided by a district
line and proposed to be used for a building or use that is not permitted
by right in both districts (in Lexington or not), such building or
use must comply with the dimensional standards of § 135-4.0,
as if the district boundary line were a lot line.
4.1.3
Lots Located in More than One Municipality. When a lot is partially
in the Town of Lexington and partially in an adjacent municipality,
the provisions of this bylaw are applied to the part of the lot in
Lexington as if the entire lot were in Lexington.
4.1.4
One Dwelling Per Lot. More than one dwelling on a lot is prohibited,
unless specifically authorized by other provisions of this bylaw.
4.2.1
Change in Lot That Results in Noncompliance. No conforming lot may
be changed to make it nonconforming.
4.2.2
Lot Regularity. No structure other than a solar energy system may
be erected on any lot that does not have an area in which a circle,
the diameter of which is 80% of the minimum lot frontage, tangent
to the lot frontage and within all other lot lines, may be located.
[Amended 11-8-2021 STM by Art. 14]
4.2.3
Lot Area.
[Amended 11-8-2021 STM by Art. 14]
1.
Lot Area. No structure other than a solar energy system may be erected
on any lot that does not have at least the minimum lot area set forth
in Table 2 for the district in which the lot is located.
2.
Developable Site Area. No dwelling may be erected on any lot that
does not contain a contiguous developable site area that is at least
90% of the minimum lot area for the district in which the lot is located.
4.2.4
Lot Frontage.
1.
Minimum Lot Frontage Required. No structure other than a solar energy
system may be erected on any lot that does not have at least the minimum
frontage set forth in Table 2[1] for the district in which the lot is located on a street.
Frontage on unaccepted ways in existence prior to the adoption of
the Subdivision Control Law must receive a favorable determination
from the Planning Board. Ways laid out, but not constructed, may not
be used as frontage.
[Amended 11-8-2021 STM by Art. 14]
[1]
Editor's Note: Table 2 is included as an attachment to this chapter.
2.
Designation of Frontage Street. When a lot is bounded by more than
one street, any one of them, but only one, must be designated as the
frontage street, provided the street meets the requirements for minimum
lot frontage described in this bylaw. In the case of a lot bounded
by two streets forming an interior angle of more than 135°, their
combined frontage may be used to satisfy the lot frontage requirement.
3.
Measurement of Lot Frontage. Frontage is measured in a continuous
line along the sideline of the street right-of-way between the points
of intersection of the side lot lines with the street right-of-way
line. The measurement of lot frontage excludes jogs in the street
width, backup strips and other irregularities in the street line.
In the case of a corner lot, the owner may extend to the midpoint
of the curve connecting street lines, instead of to their intersection.
4.
Access. An owner must provide a means of access for vehicles from
the frontage street to a principal building for emergency services,
for deliveries, and for off-street parking. Alternatively, the owner
may provide the access from another street provided it can be demonstrated
that it is both physically and legally possible to provide access
from the designated frontage street.
5.
Frontage Reduction on Curves. Where more than half of the lot frontage
is on a circular turnaround, or on a curve of less than one-hundred-foot
radius, frontage may be reduced to not less than 60% of the distance
required in Table 2 if the distance between the side lot lines, measured
along the arc parallel to the street line at the same distance from
the street line as the front yard setback required by Table 2, is
not less than the minimum lot frontage required by Table 2.
6.
Frontage on Turnaround in CRO Districts. In CRO Districts where a
lot abuts on a dead-end turnaround part of a street and also abuts
on such street before the turnaround, the frontage may be measured
in part along the street line before the turnaround and in part along
a projection of the course of such street line through and beyond
the turnaround, provided that the lot has frontage of not less than
60 feet on the street, including such turnaround.
4.2.5
Structures Below Ground. Where the upper elevation of a structure
or building is below the elevation of the natural grade, and such
structure is covered by earth to a depth sufficient to support vegetation,
such structure may be located in a required front, side or rear yard,
but no closer than five feet to a lot line. Open grates or small ventilation
shafts servicing the part of the structure below ground may be located
in the required yard.
4.2.6
Accessory
Buildings in Setbacks. One accessory building, including tool or storage
sheds for household equipment or other similar accessory use, but,
for the purposes of this section, not including garages or chicken
coops, may be located in a side or rear yard, but no closer than five
feet to a lot line, provided that the accessory building covers less
than 150 square feet and that neither the height nor the length of
such accessory building is greater than 12 feet.
[Added 3-31-2021 ATM by Art. 41]
4.3.1
Structures Other than Buildings.
[Amended 11-19-2020 STM
by Art. 13; 11-8-2021 STM by Art. 12]
1.
The maximum height, in feet, for structures other than buildings
may not exceed the maximum height for buildings as set forth in Table
2.[1]
[1]
Editor's Note: Table 2 is included as an attachment to this chapter.
2.
Structures other than buildings may be located in a minimum required
front, rear or side yard, provided the height of the structure is
not greater than its horizontal distance from the lot line, except
that:
a.
Structures
of any height which are required to enable access for disabled persons
may be located anywhere on a lot;
b.
A fence
not greater than six feet in height may be located on or closer to
a side or rear lot line;
c.
A fence
or retaining wall not greater than four feet in height may be located
on or closer to a front lot line; and
d.
Supporting
posts for a fence may extend six inches higher than the top of a fence.
4.
Structures shall not interfere with safe stopping sight distance
on a street.
5.
Where two
or more fences or retaining walls are separated by a distance that
is less than the height of the highest such structure, all such structures
shall be considered a single structure and their height shall be equal
to the combined height of the structures.
7.
A solar
energy system may be located over any paved parking lot.
4.3.2
Structures on a Building. Structures erected on a building and not
used for human occupancy may exceed the maximum height of a building
in feet provided no part of the structure is more than 20 feet higher
than the upper elevation of the building and the total horizontal
coverage of such structures on the building other than solar energy
systems does not exceed 25%.
[Amended 11-19-2020 STM
by Art. 13]
4.3.3
Calculating Height for Segmented Buildings. Where a building is on
a sloping site or has some stories that do not extend for the full
building coverage, the height in feet and number of stories of the
several elements of the building may be computed separately provided
that neither the maximum height in feet nor the number of stories
in any one element exceeds that permitted by Table 2.
4.3.4
Special Permit. The SPGA may grant a special permit for structures, but not buildings, to exceed the maximum height in feet otherwise allowed by § 4.3, or the percentage of horizontal coverage of structures erected on a building specified above, provided it makes a determination that the structure is compatible with the scale of the neighborhood and does not intrude on the solar access of any adjoining lot.
4.3.5
Height of Dwellings Near Lot Lines. The height of a one-family or
two-family dwelling may not exceed the maximum height from Table 2
or 20 feet plus 4/3 times the smallest distance from the dwelling
to a lot line, whichever is less.
[Added 3-30-2016 ATM
by Art. 39]
[Added 3-30-2016 ATM
by Art. 41]
4.4.1
Purpose. Lexington seeks to have a socially and economically diverse community, both over the whole of the community and within its neighborhoods. In support of that fundamental social goal, a basic housing goal is to provide housing opportunities supportive of the population diversity we seek. The Town encourages small- and medium-sized housing stock, in the interest of providing diverse housing sizes throughout the Town, § 4.4 limits the massing of buildings, which may impact owners of abutting properties, the streetscape, landscape, and the character of the neighborhood and Town.
4.4.2
Maximum Allowable Residential Gross Floor Area Tables. The total
gross floor area of all buildings on a lot containing a one-family
or two-family dwelling may not exceed the amount listed in Table 4.4.2.2
based on lot area, except that:
[Amended 4-24-2023 ATM by Art. 40[1]]
a.
Buildings
for which a building permit application has been submitted before
January 1, 2024, may be extended, altered, reconstructed or structurally
changed so long as the total gross floor does not exceed that in Table
4.4.2.1 below based on lot area. For the purposes of this § 4.4.2,
extension, alteration, reconstruction, and structural change shall
not include any construction which involves demolition of more than
50% of the primary building's shell exclusive of demolition of a single-story
attached garage. For purposes of calculating the percentages of any
demolition under this subsection, all demolition shall be taken into
account which commenced, or could have commenced, pursuant to an issued
permit within two years prior to the date of any request for any permit
to construct, reconstruct, alter, add, extend or otherwise structurally
change any structure.
b.
For the purposes of § 6.12.3.7(a), Table 4.4.2.1 shall
be used to determine the gross floor area permitted based on a proof
plan.
|
Table 4.4.2.1
| |
|---|---|
|
Lot Area
(in square feet)
|
Maximum Gross Floor Area
(in square feet)
|
|
0 to 5,000
|
0.8 * lot area
|
|
5,000 to 7,500
|
4,000 + 0.55 * (lot area - 5,000)
|
|
7,500 to 10,000
|
5,375 + 0.23 * (lot area - 7,500)
|
|
10,000 to 15,000
|
5,950 + 0.2 * (lot area - 10,000)
|
|
15,000 to 30,000
|
6,950 + 0.16 * (lot area - 15,000)
|
|
More than 30,000
|
9,350 + 0.16 * (lot area - 30,000)
|
|
Table 4.4.2.2
| |
|---|---|
|
Lot Area
(in square feet)
|
Maximum Gross Floor Area
(in square feet)
|
|
0 to 5,000
|
0.76* Lot Area
|
|
5,000 to 7,500
|
3,800 + 0.42 * (lot area - 5,000)
|
|
7,500 to 10,000
|
4,850 + 0.12 * (lot area - 7,500)
|
|
10,000 to 15,000
|
5,150 + 0.11 * (lot area - 10,000)
|
|
15,000 to 30,000
|
5,700 + 0.1 * (lot area - 15,000)
|
|
More than 30,000
|
7,200 + 0.1 * (lot area - 30,000)
|
[1]
Editor's Note: This article also stated that the amendments
adopted to this section shall take effect on 1-1-2024.
4.4.3
Special Permit. Pursuant to § 9.4, the SPGA may grant a special permit for a building to exceed the maximum gross floor area otherwise allowed by § 4.4 provided that the SPGA finds that the desired relief may be granted without substantial detriment to the neighborhood and without derogating from the intent and purpose of this bylaw including Town policy documents that define housing goals. In addition to the criteria in § 9.4.2, the SPGA shall find that:
a.
The project is compatible with the scale of the neighborhood;
b.
The massing of the project does not adversely impact the solar access
of adjoining lots;
c.
Noise generated by fixed plant equipment, such as, but not limited
to, air conditioners, pumps, fans, and furnaces, does not adversely
impact adjoining lots; and
d.
The project design addresses specific neighborhood and Town concerns.
[Added 10-14-2020 STM by Art. 9]
4.5.1
Purpose. The purposes of this section are to preserve and protect
groundwater; to maintain and enhance the public safety, environment,
health, and general welfare by establishing minimum requirements;
and to establish procedures to control the adverse effects of building
basement floors nearer than two feet from the estimated seasonal high
groundwater table (ESHGWT), including basement flooding, pumping and
discharge of groundwater to neighboring properties, discharging groundwater
to the public way, and illicit connections to the Town's sewer and
stormwater connections.
4.5.2
ESTIMATED SEASONAL HIGH GROUNDWATER TABLE (ESHGWT)
Definitions.
The estimated highest level to a zone of saturation in the
soil in most years under normal wet season, as determined by a registered
professional engineer, a qualified soil scientist or licensed soil
evaluator.
4.5.4
Conditions and Requirements. The vertical distance between the finished basement floor of any dwelling shall not be less than two feet above the ESHGWT. Permission for a vertical distance less than two feet above the ESHGWT may be granted if the applicant provides sufficient evidence that a proposed lesser vertical distance will not impact the structure being proposed in a manner contrary to the purposes of this § 4.5, any other structures or constructed facilities, or the functions of the natural groundwater system (such as base flow maintenance) and if all of the following conditions are met:
1.
Detailed engineering plans, certified by a registered professional
engineer showing a foundation and perimeter drain management system
and roof stormwater management system(s) that will mitigate and control
groundwater discharge and stormwater runoff, are provided;
2.
The provided foundation and perimeter drain discharge management
system and roof stormwater management system plans have been reviewed
by the Building, Conservation, Health and Engineering Departments
and comments adequately addressed;
3.
Roof drains and downspouts connect to a stormwater management system
designed by a registered professional engineer; and
4.
The applicant has agreed to pay the fee for consulting services to
perform engineering review pursuant to the provisions of MGL c. 44, § 53G.
