Blaine allows attached ADUs by right through an administrative permit, but a 2026 ordinance removed detached ADUs from every zoning district - a decision that is currently part of an active, contested legal dispute.
Last verified: August 20264/10 · Limited (attached only)
960 sq ft*
Max ADU size
Match house
Max height
Required
Owner-occupancy
By-right
Permit type
This page summarizes Blaine City Code Chapter 129 §129-23 (Standards for Accessory Dwelling Units) as amended by Ordinance 26-2601, for general reference - it is not legal advice. Regulations change; always confirm current requirements with the City of Blaine before designing or applying for permits. See sources below.
Zoning & size requirements
What you're allowed to build
Detached ADUs are currently banned in Blaine. Blaine originally allowed both attached and detached ADUs starting with Ordinance 21-2489 (2021). After a lawsuit (Pepin v. Blaine, backed by the Institute for Justice) over a denied detached-ADU application, the City Council paused new applications and then, on March 18, 2026, voted 5-1 to approve Ordinance 26-2601, removing detached ADUs from every zoning district while keeping attached ADUs allowed. The Institute for Justice and the St. Paul Area Association of Realtors have publicly opposed the ban on constitutional grounds, and the legal situation is still active as of this writing - check with the City of Blaine for the latest status before assuming these rules are final.
Lesser of 50% of the primary home's finished square footage or 960 sq ft (R-1, R-1A, R-1AA, R-1B, DF districts); 1,200 sq ft cap in RE/FR districts
Follows standard living-space height rules for the district - no separate ADU height cap
Detached ADUs are not currently allowed anywhere in the city - see note above
Allowed zoning districts
R-1, R-1A, R-1AA, R-1B, RE, FR, and DF (Development Flex). Confirm your parcel's zoning district with the City of Blaine.
Additional standards
Setbacks, parking & other rules
Setbacks
Attached ADUs follow standard living-space setbacks for the district - no separate ADU setback schedule.
Parking
The home and ADU together must have at least 3 off-street parking spaces with direct access (garage or paved surface). A driveway space located in front of a garage does not count toward this requirement.
Units per lot
1 ADU maximum per property. Occupancy is capped at 2 adults (plus their children). Utilities cannot be separately metered.
Owner-occupancy
Required. Either the primary home or the ADU must be occupied by the property owner, and this requirement is recorded against the property as a deed restriction.
Rental licensing
The ADU is treated as a separate dwelling for rental-licensing purposes if it's occupied by anyone who isn't the owner or a family member.
Permit type & fee
Administrative permit (staff-level review, no City Council hearing needed for attached ADUs), plus a $200 ADU registration fee per Blaine's fee schedule effective January 1, 2026.
Ordinance history
How Blaine's ADU rules got here
2021ADUs first allowed. The City Council adopted Ordinance 21-2489 (first reading Dec. 6, second reading and adoption Dec. 20, 2021), permitting both attached and detached accessory dwelling units in residential districts.
Apr.-May 2025The Pepin case. Alex and Lynda Pepin applied to build a detached ADU to house a family exiting homelessness. The Planning Commission approved it 4-2 in April, but the City Council denied the permit in May, citing the ordinance's unwritten "intent."
June 2025Moratorium imposed. Two weeks after the denial, the Council paused all new ADU applications for up to a year at a June 16, 2025 workshop, directing staff to review the ordinance's regulations and intent.
2025Lawsuit filed. After a revised "mother-in-law unit" proposal was also denied, the Pepins sued the city in Anoka County District Court with backing from the Institute for Justice.
Mar. 18, 2026Ordinance 26-2601 adopted. Following a January 5, 2026 workshop directing staff to remove detached ADUs from city code and a March 2 first reading, the Council voted 5-1 (Council Member Chris Ford dissenting) to remove detached ADUs from every zoning district while keeping attached ADUs. The Institute for Justice and the St. Paul Area Association of Realtors publicly opposed the change.
The Pepin lawsuit remains active as of this writing, and the ban itself was adopted by a single-vote margin over public opposition - this is a live legal and political issue, not settled history. Confirm the latest ordinance status with the City of Blaine before finalizing any ADU plans, and don't assume this page's snapshot is the final word.
Permit process
How Blaine ADU permitting works
1
Confirm eligibility
Verify your lot is zoned R-1, R-1A, R-1AA, R-1B, RE, FR, or DF, and that your ADU will be attached to the primary home - detached units are not currently permitted.
2
Prepare your plan set
Put together construction drawings (floor plans and elevations) showing the attached ADU, plus a site plan confirming the 3 required off-street parking spaces.
3
Submit registration + fee
File the ADU registration application along with the $200 fee.
4
Administrative permit review
City staff review the application at the staff level - no City Council hearing is required for attached ADUs. No single published ADU-specific review timeline was found; confirm current turnaround when you submit.
5
Building permit, plan review & inspections
Obtain standard building permits before construction begins; plan review is billed at 65% of the building permit fee. Once permitted, expect the standard framing, plumbing, electrical, and final inspections, scheduled through Building Inspections at 763-785-6177 (or 763-785-6170, option 1) - plan for 3-4 business days' notice.
6
Deed restriction recorded
The owner-occupancy requirement is recorded against the property as a deed restriction.
Review timelines weren't published in a single ADU-specific schedule at time of writing - confirm current timelines with the City of Blaine. Building Inspections can also be reached by email at Building@BlaineMN.gov.
Budgeting
What it costs to build an ADU in Blaine
Basement conversion
Roughly $110,000-$220,000, based on local contractor estimates and regional reporting
Addition or above-garage buildout
Roughly $135,000-$250,000 - detached ADUs aren't currently an option in Blaine, so this tends to be the larger attached path
ADU registration fee
$200 flat, per Blaine's fee schedule effective January 1, 2026
City building permit & plan review fees
Tiered by project valuation - for example, a $150,000 project would owe roughly $1,357 for the building permit plus another $882 for plan review (65% of the permit fee), per the fee schedule effective January 1, 2026. Get a project-specific figure from Building Inspection.
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
These are general ranges from local contractor estimates, regional reporting, and Blaine's official fee schedule, not project quotes - actual cost depends heavily on lot conditions, finishes, and whether utilities need to be extended. Minnesota's climate adds real cost too: even an attached ADU needs full insulation and a code-compliant building envelope, not just interior finishing.
Before you apply
Tips for a smooth approval
Confirm your project is attached, not detached, before you design. Ordinance 26-2601 (2026) removed detached ADUs from every zoning district, and the underlying dispute is still active - a design centered on a detached structure could hit a dead end.
Get the owner-occupancy deed restriction in writing early. Blaine records this against the property, so factor it into your title work and any future sale plans.
Plan your 3 parking spaces before you finalize the floor plan. A driveway space in front of a garage doesn't count, so make sure the site plan shows compliant off-street spaces.
Budget the $200 registration fee plus valuation-based permit and plan-review fees, not just construction, when comparing contractor bids.
Watch for further ordinance changes. Given the active Pepin lawsuit and continued opposition from the Institute for Justice and area Realtors, confirm the latest rules with Building Inspection before finalizing plans.
FAQ
Common questions
Can I build a detached backyard ADU in Blaine?
As of 2026, no. Ordinance 26-2601 removed detached ADUs from every zoning district; only attached ADUs are currently allowed. This is part of an active, contested legal dispute (an Institute for Justice-backed lawsuit), so it's worth checking the city's latest ordinance status before ruling anything out.
Why did Blaine ban detached ADUs?
Blaine originally allowed both attached and detached ADUs starting with Ordinance 21-2489 (2021). After a lawsuit over a denied detached-ADU application (Pepin v. Blaine, backed by the Institute for Justice), the City Council imposed a moratorium on new ADU applications, then voted 5-1 on March 18, 2026 to approve Ordinance 26-2601, removing detached ADUs citywide while keeping attached ADUs. The Institute for Justice and the St. Paul Area Association of Realtors have publicly opposed the ban on constitutional grounds, and the dispute is still active.
Do I need to live on the property?
Yes. Either the primary home or the ADU must be owner-occupied, and this is recorded as a deed restriction against the property.
How much parking do I need?
At least 3 off-street spaces total for the home and ADU combined, with direct access via garage or paved surface.
What's the registration fee?
$200, per Blaine's fee schedule effective January 1, 2026.
How many people can live in the ADU?
Occupancy is capped at 2 adults, plus their children.
How much does an ADU cost to build in Blaine?
Blaine doesn't publish ADU-specific cost data. Based on local contractor estimates and regional reporting, a basement conversion typically runs $110,000-$220,000, and an addition or above-garage buildout $135,000-$250,000, depending on finishes and existing utility access. On top of construction, budget for the $200 registration fee, the city's valuation-based building permit and plan review fees, and the $2,485 Metropolitan Council SAC fee if your project adds a new sewer unit.
What documents do I need for the ADU registration and building permit?
Blaine's registration process requires a completed ADU application alongside the $200 fee; the building permit itself needs construction drawings (floor plans and elevations) showing the attached ADU and a site plan confirming the 3 required parking spaces. Confirm the exact document checklist with Building Inspection before you apply.
Can I rent my ADU out on Airbnb or a short-term rental platform?
Blaine treats the ADU as a separate dwelling for rental-licensing purposes whenever it's occupied by someone who isn't the owner or a family member, but the sources reviewed for this page didn't address short-term rental platforms specifically. Confirm current short-term rental rules and any registration requirements with the city before listing the unit.
