Portland, ME Zoning

14 districts. 5 overlays.
This profile is an earlier edition — some fields may be incomplete. An updated profile is in progress.

Districts

res_sf 7mu 4ind 3
CodeNameCategory Min lotHeight CoverageFAR Du/acParking Setbacks F/S/R
RN-1Residential Neighborhood 1res_sf10,000 sf35 ft0.40.56225 / 25 / 10
RN-2Residential Neighborhood 2res_sf6,500 sf35 ft0.350.510225 / 25 / 10
RN-3Residential Neighborhood 3res_sf6,000 sf35 ft0.50.5225 / 25 / 10
RN-4Residential Neighborhood 4res_sf5,000 sf35 ft0.50.5225 / 25 / 10
RN-5Residential Neighborhood 5res_sf5,000 sf35 ft0.50.5225 / 25 / 10
RN-6Residential Neighborhood 6res_sf5,000 sf35 ft0.50.5225 / 25 / 10
RN-7Residential Neighborhood 7res_sf5,000 sf35 ft0.50.5225 / 25 / 10
B-1Business 1mu5,000 sf35 ft0.50.5225 / 25 / 10
B-2Business 2mu5,000 sf35 ft0.50.5225 / 25 / 10
B-2bBusiness 2bmu5,000 sf35 ft0.50.5225 / 25 / 10
B-2cBusiness 2cmu5,000 sf35 ft0.50.5225 / 25 / 10
I-LIndustrial Lightind5,000 sf35 ft0.50.5225 / 25 / 10
I-MIndustrial Mediumind5,000 sf35 ft0.50.5225 / 25 / 10
I-HIndustrial Heavyind5,000 sf35 ft0.50.5225 / 25 / 10

Confidence: confirmed partial under review not found

Overlays

CFR
Coastal Flood Resilience
FP

Applies to: Residential, Commercial, Mixed-Use, Office

coverage adjustment (%)-10
setback addition (ft)15
HD
Historic
HP

Applies to: Residential, Commercial, Office, Mixed-Use

coverage adjustment (%)-10
density multiplier-0.2
lot size multiplier0.15
A1
Shoreland Zone
ENV

Applies to: Residential, Commercial, Mixed-Use, Office

coverage adjustment (%)-10
setback addition (ft)15
A1
Floodplain Zone
FP

Applies to: Residential, Commercial, Mixed-Use, Office

coverage adjustment (%)-10
setback addition (ft)15
A1
Resource Protection Zone
spec

Applies to: Residential, Commercial, Mixed-Use, Office

coverage adjustment (%)-10
setback addition (ft)15

Adopted building codes

Cities > 4,000 pop

2021
2021
2020
2021
IECC (Residential)
2021
IECC (Commercial)
2021

Click a code label to open its state-by-state adoption atlas.

Formulas

Definitions

height
Grade to highest point of structure.
lot_coverage
Building footprint / lot area.
far
Gross floor area / lot area.
du_ac
Dwelling units per gross acre.
setback_front
Front property line to nearest building face.
setback_side
Side property line to nearest building face.
setback_rear
Rear property line to nearest building face.
parking
Spaces per dwelling unit unless noted.

Capacity calculations

max_footprint_sf
lot_area_sf * lot_coverage
max_gfa_sf
lot_area_sf * far
buildable_width_ft
lot_width_ft - setback_side_ft * 2
buildable_depth_ft
lot_depth_ft - setback_front_ft - setback_rear_ft
max_stories_approx
max_height_ft / 10

Massing explorer

Interactive 3D comparison across every district. Drag to orbit, scroll to zoom, use the slider to walk districts, and toggle applicable overlays in the right-side panel.

Sort by
LOW
HIGH
drag to orbit · scroll to zoom
Max height
ft
Floor area ratio
Lot coverage
%
Setbacks (F / S / R)
ft
Parking
/unit
Max density
du/ac
Min lot size
sf
Copy zoning profile
Loading…
District Category Height FAR Coverage Setbacks Parking Density Min lot Overlays

Research status

Data quality

11%completeness7 confirmed37 partial18 inferred
Documented gaps
  • Quirks not populated — requires markdown source review

Known issues

schema:v1-legacypriority:lowdata:gaps-present