A. 
General. All structures hereafter erected in any district shall be located on a lot such that all of the requirements set forth in the following table are complied with, except where specifically exempted by this chapter or by the General Laws.
B. 
Changing lot dimensions. No existing lot shall be changed in size or shape so as to result in violation of the requirements set forth below.
C. 
Statutory exemptions. MGL C. 40A, § 6, exempts certain residential lots from some of those requirements and exempts for some time certain lots on approved subdivision plans. (See also § 173-11.)
D. 
Street setback. On corner and through lots, street setbacks shall be maintained from each abutting street or way which qualifies to provide lot frontage for division of a parcel into lots. Except where stated to the contrary, all street setbacks shall be measured from the legal boundary of the way, but, where no such boundary is established, the setbacks shall be measured from a line 25 feet from the center of the traveled roadway.
Lots having less than the normally required lot frontage may be created and built upon for residential use, provided that such lots are shown on a plan endorsed by the Planning Board "Approved for Reduced Lot Frontage." Plans shall be so endorsed if meeting each of the following, but not otherwise:
A. 
Each lot shall have frontage of at least 35 feet.
B. 
Egress over that frontage shall create no greater hazard owing to grade and visibility limitations than would be normal for a standard lot in the same area.
C. 
Each lot must contain at least 40,000 square feet more than the minimum otherwise required, without counting the area within any access strip. "Access strip" in this case shall mean any portion of the lot between the street and the point where lot width equals 100 feet or more.
D. 
All other normal lot requirements as specified in the Intensity of Use Schedule shall be met.
E. 
Each lot with less frontage than normally required shall be capable of containing a square with sides equal to the normally required lot frontage. Said square shall be shown on the plan submitted to the Planning Board for endorsement.
F. 
No lot having less than normally required frontage shall be endorsed by the Planning Board if its access strip abuts another such lot.
G. 
Plans of reduced frontage lots shall show the frontage of each lot abutting its access strip and, if any such lot is a reduced frontage lot, shall show the location of that lot's access strip.
[Added 5-9-1988 ATM, Art. 14]
[Added 5-4-1998 ATM, Art. 33]
The shape of all lots shall conform to the following requirement:
173-29 Formula.tif
Where:
A
=
The lot area in square feet.
P
=
The lot perimeter in feet.