What Can I Build Here? Interactive Zoning Map
Mapping local zoning boundaries…
Permitting an ADU or home in Portland
ADU verdict · Portland
Building an ADU here
- ADUs are allowed by right (administrative review only).
- No owner-occupancy requirement.
- No sprinkler requirement for 1–2 units.
- No flat square-foot maximum; ADU gross floor area is capped at two-thirds (2/3) of the principal unit's gross floor area per Portland Land Use Code §6.6.2.A.9 (a ratio, not a fixed ceiling).
- Short-term rentals: permitted.Short-term-rental rules vary by location here — Peaks Island: prohibited. Confirm the rule for your specific parcel.
- Max ADU size
- ⅔ of main home
- Building-permit review
- 4-6 wks
- Permits to build
- Building permit+ trade sub-permits
- How you file
- Online portal
The typical order
confirm with the code officeWhich permits may apply — sequence is typical; some steps run in parallel.
New home: 19 permits may apply. Approvals: Typically no public hearing.
- ApprovalsTypically no public hearing
- Minor Site Plan (Residential) Application
- Site & utilities
- Street Opening Permit
- Stormwater Quality Permit
- Subsurface Wastewater Permit
- Water Service
- Build
- Building Permit
- Electrical Permit
- Plumbing Permit
- HVAC Permit
- Fuel Tank Permit
- Site Inspection
- Demolition Permit
- Impact Fees (Recreation, Transportation, Wastewater)
- Internal Plumbing Permit
- Final sign-off
- Certificate of Occupancy
Your land's triggers
Depends on your lotThe steps above are Portland's standard permit path — which ones apply depends on your project. What's below depends on where your lot sits, and the zoning map can't see it.
Parcel diagnostics unscanned- Flood hazard
- Wetland / vernal pool (NRPA)
- Shoreland
- Historic district
- Site & soil conditions
- Per-lot fee impact
Launching soonThis page names the questions; your parcel gives the answers — which fire, why, and cited. That's the paid lot report.
Showing 15 of 19 permits by name — the rest are lot-dependent or listed in the full permit ledger below.
Where to apply
- Department
- Permitting & Inspections
- Phone
- (207) 874-8703
- Address
- 389 Congress Street, Portland, Maine 04101
Intake details current as of April 10, 2026. Confirm with the code office before applying.
Permits you may need
- Building PermitOnline portal· 4-6 wksApply
- Electrical PermitOnline portal· 4-6 wksApply
- Plumbing PermitOnline portal· 4-6 wksApply
- HVAC PermitOnline portal· 4-6 wksApply
- Fuel Tank PermitOnline portal· ~2-4 wksApply
- Certificate of OccupancyOnline portalApply
- Minor Site Plan (Residential) ApplicationOnline portal· 4-6 wksApply
- Site InspectionOnline portalApply
- Historic ReviewOnline portal· 2-4 wksApply
- Flood Hazard Development PermitOnline portal· 2-4 wksApply
- Street Opening PermitOnline portal· 1-2 wksApply
- Stormwater Quality PermitOnline portal· 4-6 wksApply
Review times run longer in peak building season — confirm current turnaround with the code office.
This is public-record guidance, not legal advice — verify with the code office before applying. Maine fee schedules revise annually on July 1.
ADUs allowed by right (LD 2003). Portland permits up to 2 per lot (Portland Land Use Code · Adopted Dec 4, 2024). Search your address to check your lot.
Portland Zoning Districts
V-STARA™ zoning data provides screening-level feasibility estimates. Final dimensional constraints and requirements must be verified during the formal municipal permitting phase.