Lynn, MA Building Setbacks & Zoning: Lot Coverage Limits (2026)

1 of the Zoning Ordinance states that no building or structure may be constructed, enlarged or altered except in conformance with the Table of Dimensional Requirements, and that impervious lot coverage is defined as the portion of a lot covered with impervious surfaces, including buildings and impervious driveways. The table sets a different ceiling for every district: 65% in the R1 and R2 districts, 80% in R3 and R4, 70% in B1, 85% in B2, 100% in the BC business-core district, 80% in M1, 100% in M2, 75% in the MV district, 85% in RD, 70% in RT, and 95% in both industrial districts, IL and IH.

a spells out how coverage is measured: it runs from the outside of the exterior walls at the ground story, including covered porches and other building components, and for porous asphalt, pervious concrete, paving stones or grass pavers, the lot coverage and permeable area is calculated using the runoff coefficient supplied by the manufacturer and certified by a design professional, a credit not available for ordinary poured concrete or asphalt. 5 feet from a building under 35 feet tall may extend past the minimum side and rear setback, but the ground beneath those projections still cannot be counted as open space against the impervious lot coverage cap. No existing lot may be changed in size or shape so as to push it into a coverage violation.