ADU Rules

Plymouth ADU Rules (2026)

Plymouth allows ADUs by right through an administrative permit under City Code §21190.04. Ordinance No. 2024-22 and Ordinance No. 2026-01 significantly expanded eligibility, from newer subdivisions only to essentially all single-family homeowners citywide.

Last verified: August 2026 6/10 · Moderate
700 sq ft
Max detached ADU size (or 30% of rear yard, if less)
1,000 sq ft
Max attached/internal ADU size (or 30% of home, if less)
Required
Owner-occupancy
Citywide (2026)
Eligibility expanded beyond newer subdivisions
This page summarizes Plymouth City Code §21190.04 (Accessory Dwelling Units), as amended by Ordinance No. 2026-01 (adopted February 10, 2026) and Ordinance No. 2024-22 (adopted September 24, 2024), for general reference - it is not legal advice. Regulations change; always confirm current requirements with Plymouth's Inspections Division before designing or applying for permits. See sources below.
Zoning & size requirements

What you're allowed to build

ADU typeMax sizeMax heightNotes
Detached 700 sq ft, or 30% of the rear yard area, whichever is less (minimum 200 sq ft) Not clearly confirmed in available sources - confirm with the city General accessory-building setback rules under Section 21120 likely apply, but exact figures were not confirmed
Attached / internal 1,000 sq ft, or 30% of the primary home's floor area, whichever is less Not clearly confirmed in available sources - confirm with the city -

Allowed zoning districts: FRD and RSF (single-family) districts, and single-family detached dwellings in RMF and PUD districts. Historically ADUs were limited to newer subdivisions in Plymouth; Ordinance 2024-22 (Sept 2024) and Ordinance 2026-01 (Feb 2026) expanded eligibility to essentially all single-family homeowners citywide.

Additional standards

Setbacks, parking & other rules

Setbacks & heightNot clearly confirmed in available sources. General accessory-building setback rules under Section 21120 likely apply - confirm exact figures with the Inspections Division.
ParkingUncertain. Earlier drafts of the ordinance required additional off-street parking; more recent reporting suggests this requirement was removed, but we could not confirm the final current rule. Check with the city's Inspections Division.
Owner-occupancyRequired, confirmed by multiple local news sources
Short-term rentalsBanned (Airbnb/VRBO-style). Long-term rental of the ADU is allowed.
Units per lotTypically one ADU per lot. Not explicitly confirmed in available sources, but consistent with every other Twin Cities city researched.
Permit processStandard building/inspection permitting through the Inspections Division; no ADU-specific fee schedule was found
Permit process

How Plymouth ADU permitting works

1

Confirm eligibility

Verify your property is in the FRD or RSF district, or is a single-family detached home in the RMF or PUD district.

2

Submit administrative permit application

ADUs are reviewed administratively under City Code §21190.04, not through a discretionary conditional use permit process.

3

Plan review

Reviewed by the city's Inspections Division for zoning and building code compliance.

4

Building permit & inspections

Complete the standard building permit and inspections process before occupancy.

No ADU-specific permit fee schedule or review timeline was found in available sources at time of writing - confirm current figures with the Inspections Division at 763-509-5430.

FAQ

Common questions

Do I need to live on the property to build an ADU in Plymouth?
Yes. Owner-occupancy is required, per multiple local news sources covering the ordinance.
Can I list my ADU on Airbnb?
No. Short-term rentals of ADUs are banned in Plymouth. Long-term rental of the ADU is allowed.
What's the size difference between detached and attached ADUs?
Detached ADUs are capped at 700 sq ft (or 30% of the rear yard, whichever is less). Attached or internal ADUs are capped at 1,000 sq ft (or 30% of the primary home's floor area, whichever is less).
Which properties qualify?
Historically, Plymouth limited ADUs to newer subdivisions. Ordinance No. 2024-22 (adopted September 2024) and Ordinance No. 2026-01 (adopted February 2026) significantly expanded eligibility, so ADUs are now allowed on essentially all single-family lots in the FRD and RSF districts, plus single-family detached homes in RMF and PUD districts.

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Sources

Where this information comes from