St. Louis Park has allowed ADUs by right since November 2020, reviewed through a standard building permit rather than a conditional use permit. The city's full zoning code was recodified in March 2025 under Ordinance 2692-25.
Last verified: August 20266/10 · Moderate
40% of home*
Max ADU size
15 ft*
Max height
Likely required*
Owner-occupancy
By-right
Permit type
This page summarizes the City of St. Louis Park's ADU program page and zoning code (recodified March 2025 under Ordinance 2692-25) for general reference - it is not legal advice. Regulations change, and some figures below could not be fully confirmed; always confirm current requirements with St. Louis Park Planning & Zoning before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
ADU type
Max size
Max height
Notes
Detached
Minimum 200 sq ft is confirmed. The maximum size could not be reliably confirmed - available sources conflicted (one figure applied to ADUs, another may describe general accessory buildings rather than ADUs specifically). Confirm the current maximum directly with the city.
15 ft, with unspecified exceptions noted by the city but not detailed in available sources
-
Attached / internal
No more than 40% of the gross floor area of the principal building
Not separately specified - follows the principal structure
This 40% figure is corroborated across two independent sources
Allowed zoning districts
Not explicitly confirmed in available sources; ADUs are generally described as allowed on single-family residential lots. As of the March 2025 recodification, St. Louis Park's residential districts were renamed "neighborhood" districts (for example, former R-1/R-2 became N-1/N-2). Confirm your parcel's current zoning district with Planning & Zoning.
Additional standards
Setbacks, parking & other rules
Setbacks
Side (interior lot line): 5 ft. Rear: 15 ft, reduced to 5 ft if the lot abuts an alley. Front setback was not found in available sources. Under the N-1/N-2 code, accessory buildings taller than 15 ft must also sit at least 15 ft from a shared property line used for a dwelling, and any detached structure within 6 ft of the house is treated as part of the principal building for setback purposes.
Parking
No additional off-street parking is required for an ADU in general. Exception: a garage cannot be converted into an ADU unless the home's own required parking can still be accommodated (in a structure, or behind the front face of the house).
Owner-occupancy
Likely required based on the city's own ADU FAQ, which frames "Do I own and live on the property where I would like to construct an ADU?" as a threshold eligibility question - though no explicit code citation was found. Verify directly with the city.
Units per lot
Not explicitly confirmed in available sources; presumed 1, consistent with every other Twin Cities city researched.
Building code
Must meet 2020 Minnesota Residential Code dwelling unit standards
Rental license
Required if the ADU is rented. A building permit, plus possibly electrical, mechanical, and plumbing permits, is also required.
Ordinance history
How St. Louis Park's ADU rules got here
2020ADUs first allowed. The City Council adopted a code amendment on November 13, 2020, permitting accessory dwelling units citywide as part of St. Louis Park's push to broaden housing options.
2025Zoning code recodified. Ordinance 2692-25, adopted March 17, 2025 and effective March 28, 2025, was the city's first comprehensive zoning rewrite since 1992. It renamed residential zoning districts as "neighborhood" districts (N-1, N-2, etc.) and reviewed standards for every housing type, including ADUs.
Worth knowing: under the new N-1/N-2 code, all accessory buildings on a lot - garages, sheds, and any detached ADU - are capped together at the lesser of 800 sq ft or 25% of the backyard. It isn't confirmed whether that general accessory-building limit is the same number that applies specifically to a detached ADU, so treat it as a starting point for a conversation with Planning & Zoning, not a final answer.
Permit process
How St. Louis Park ADU permitting works
1
Confirm eligibility
Includes confirming you own and live on the property - see the owner-occupancy note above - and checking which zoning district (N-1, N-2, etc.) your lot falls under since the 2025 recodification.
2
Prepare your plan set
Put together a site plan and construction drawings (floor plans and elevations) for the ADU; a certified survey may be required depending on the project. Confirm the exact document checklist with Building & Energy.
3
Submit through ePermits
Residential permits are submitted online through the city's ePermits portal; construction plans are uploaded through ProjectDox once the application is in. Electrical, mechanical, and plumbing permits may also be required.
4
Plan review
Reviewed by Planning & Zoning for compliance with the recodified zoning code (Ordinance 2692-25, adopted March 2025). A single published ADU-specific review timeline wasn't available - confirm current turnaround with Building & Energy.
5
Inspections
Once permitted, expect the standard framing, plumbing, electrical, mechanical, and final inspections. Schedule inspections through the city's eScheduling system or by calling 952-924-2588.
6
Rental license (if renting)
Apply for a rental license before placing tenants in the ADU.
Permit fees are based on the city's valuation-based fee schedule; an ADU-specific figure wasn't published as a standalone document at time of writing. Confirm current fees and timelines with St. Louis Park Building & Energy / Inspections at 952-924-2588, or Planning & Zoning at 952-924-2575.
Budgeting
What it costs to build an ADU in St. Louis Park
Garage conversion
Roughly $65,000-$160,000, based on local contractor estimates and regional reporting
Basement conversion
Roughly $110,000-$220,000, depending on existing ceiling height and utility access
New detached ADU
Roughly $135,000-$300,000+ for a code-compliant, fully insulated freestanding unit - actual cost depends heavily on the maximum size your lot qualifies for (see the size-cap note above)
SAC fee
$2,485 per unit in 2026, charged by Metropolitan Council Environmental Services on new units that add sewer demand; many basement conversions don't trigger it - confirm with the city
City permit & plan review fees
Valuation-based; get a project-specific quote from Building & Energy before you budget
These are general ranges from local contractor estimates and regional reporting, not St. Louis Park-specific quotes - actual cost depends heavily on lot conditions, finishes, and whether utilities need to be extended. Minnesota's climate adds real cost too: a detached ADU is a fully insulated, freestanding structure, not just a room.
Before you apply
Tips for a smooth approval
Get your owner-occupancy plans settled first. The city's own ADU FAQ treats living on the property as a threshold question, so confirm this applies to your situation before you invest in design work.
Get the detached-ADU size cap in writing before you design. Sources conflict on whether the maximum is a general accessory-building limit or an ADU-specific number - ask Planning & Zoning for a written answer for your lot.
Know your zoning district's new name. The March 2025 recodification renamed residential districts as "neighborhood" districts (N-1, N-2, etc.) - make sure any plans or contractor references use current terminology.
Check whether a garage conversion affects your required parking. St. Louis Park won't let you convert a garage into an ADU unless the home's own required parking can still be accommodated elsewhere on the lot.
Budget for SAC and rental licensing, not just construction. The $2,485 SAC fee (where it applies) and rental license costs are easy to forget when comparing contractor bids.
FAQ
Common questions
Do I need to live on the property to build an ADU in St. Louis Park?
Likely, yes. The city's own ADU FAQ frames owning and living on the property as a threshold eligibility question, which suggests owner-occupancy is required. However, we could not find an explicit code citation confirming this as a hard rule - verify directly with the city before relying on it.
What's the max size for a detached ADU?
The minimum confirmed size is 200 sq ft. The maximum is less clear: the city's N-1/N-2 (neighborhood) zoning districts cap all accessory buildings combined - garages, sheds, and any detached ADU - at the lesser of 800 sq ft or 25% of the backyard, but it isn't confirmed whether that general accessory-building cap is the same figure that applies specifically to a detached ADU. Confirm the applicable maximum with Planning & Zoning before finalizing a design.
What's the max size for an attached ADU?
No more than 40% of the gross floor area of the principal building - this figure is corroborated across two independent sources.
Do I need extra parking?
No, not in general. The exception is a garage conversion: you can't convert a garage into an ADU unless the home's own required parking can still be accommodated elsewhere.
How much does an ADU cost to build in St. Louis Park?
St. Louis Park doesn't publish ADU-specific cost data. Based on local contractor estimates and regional reporting, garage conversions tend to run roughly $65,000-$160,000, basement conversions $110,000-$220,000, and new detached units $135,000-$300,000 or more, not counting the $2,485 SAC fee (where it applies) or city permit fees.
What documents do I need for the building permit?
St. Louis Park's ePermits system requires a complete residential building permit application with a site plan and construction drawings (floor plans and elevations) for the ADU. Depending on the project, a certified survey may also be required. Confirm the exact document checklist with Building & Energy before you submit.
What's the SAC fee, and do I always have to pay it?
SAC (Sewer Availability Charge) is a regional fee charged by the Metropolitan Council on units that add new sewer capacity demand - $2,485 per unit in 2026. Whether it applies to your project depends on the specifics, such as whether the ADU is a new connection or shares an existing one; confirm with St. Louis Park Building & Energy before you budget.
Can I rent my ADU out on Airbnb or a short-term rental platform?
St. Louis Park's ADU program materials reviewed for this page focus on standard rental licensing rather than short-term rentals specifically. If you're planning to list the unit on Airbnb or a similar platform, confirm current short-term rental rules and any registration requirements with the city before you finalize your plans.
What changed in the city's 2025 zoning code update?
The City Council adopted Ordinance 2692-25 on March 17, 2025 (effective March 28, 2025), the first comprehensive rewrite of St. Louis Park's zoning code since 1992. It renamed residential zoning districts as "neighborhood" districts (for example, the former R-1 and R-2 districts became N-1 and N-2) and reviewed standards for all housing types, including ADUs. The update didn't eliminate the ambiguity around the detached ADU size cap noted above.
