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

Leominster does not apply one impervious-coverage percentage across the whole city. Instead, Section 22-40's Table of Dimensional Regulations lists a separate 'Maximum Impervious Coverage, Percent of Total Lot Area' figure for each zoning district, and the two numbers that actually restrict coverage sit in districts with the most sensitive groundwater or density concerns. In the Water Supply Protection district (WSP), which overlays the city's aquifer recharge and reservoir watershed areas, the table sets a fifteen percent maximum, footnoted to note that the planning board may allow greater impervious coverage under Section 22-35.3.3.7 if the applicant can show the stricter groundwater-protection standards of the WSP district are still met. In the Residence B (RB) district, which permits two-family dwellings and limited apartments at higher density than the single-family RR and RA districts, the table caps impervious coverage at fifty percent.

For most other districts in the table, including RR, RA, the business (BA, BB), commercial (C), industrial (I) and mixed-use (MU1, MU2) districts, the Maximum Impervious Coverage column reads 'None,' meaning the zoning ordinance does not impose a percentage cap on paving, roofs, driveways and other impervious surfaces there; those districts are instead controlled through their minimum lot size, frontage, yard and height figures rather than a coverage ceiling. Because the applicable percentage depends entirely on which zoning district a parcel sits in, a homeowner or developer has to check the district column in Section 22-40 rather than assume a citywide figure applies.