Bloomington allows both attached and detached ADUs by right in its single-family districts, with no owner-occupancy requirement - one of the more workable ordinances among Twin Cities suburbs.
Last verified: August 2026
8/10 · ADU-friendly
1,000 sq ft*
Max ADU size
Match house
Max height
Not required
Owner-occupancy
By-right
Permit type
This page summarizes Bloomington City Code §21.302.03 (Accessory Dwelling Units) for general reference - it is not legal advice. Regulations change; always confirm current requirements with the Bloomington Planning Division 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 (new construction)
1,000 sq ft or 33% of the primary home's four-season living area, whichever is smaller (min 300 sq ft)
May not exceed the height of the primary dwelling
Up to 100 sq ft of shared mechanical space excluded from the size calculation
Attached / internal (basement, addition)
Same 1,000 sq ft / 33% formula applies
Same as primary structure
Common approach for basement conversions
Allowed zoning districts
R-1 and RS-1 only, on lots of at least 11,000 sq ft served by municipal sewer and water. Confirm your parcel's zoning district with the Planning Division.
Additional standards
Setbacks, parking & other rules
Setbacks
Front/side along a street: same as principal structure. Rear (not along a street): 15 ft. Side (not along a street): 10 ft.
Parking
No dedicated extra-space requirement - the property must continue to meet the city's standard single-family parking minimums
Units per lot
1 ADU permitted, capped at 2 bedrooms
Owner-occupancy
Not required
Building code
Must meet 2020 Minnesota Residential Code dwelling unit standards
Rental license
Required under Chapter 14 if the ADU is rented out
Short-term rentals
Prohibited citywide (§14.577(b)) - rentals under 30 consecutive days aren't allowed, for the ADU or the main house
Ordinance history
How Bloomington's ADU rules got here
2009ADUs first allowed. Ordinance 2009-18 (passed 6-22-2009) permitted attached and internal accessory dwelling units by right in the city's residential districts. Detached backyard units were not yet allowed.
2022Detached ADUs added. Ordinance 2022-39, adopted 8-8-2022 after a Planning Commission and Council review that began with an October 2021 study session, allowed detached ADUs for the first time and set the current 1,000 sq ft / 33%-of-home size formula, along with updated parking standards.
Worth knowing: for the 13 years between the 2009 ordinance and the 2022 amendment, a freestanding backyard ADU wasn't an option in Bloomington at all - only units attached to or built inside the primary home qualified. If you're looking at a detached "granny flat" or backyard cottage, that's a relatively recent option here, which is part of why local project comparables are still limited.
Permit process
How Bloomington ADU permitting works
1
Confirm eligibility
Verify your lot is zoned R-1 or RS-1, at least 11,000 sq ft, and served by municipal sewer and water.
2
Prepare your plan set
Put together a site plan, floor plans and elevations of the ADU, and floor plans of the existing house so staff can verify the 33%-of-home size calculation.
3
Submit site plan application
File with the Planning Division for site plan approval alongside your building permit application.
4
Plan review
The city reviews for zoning and building code compliance before permits are issued. Timelines vary with project complexity and time of year - confirm current turnaround with Building and Inspections.
5
Building permit & inspections
Once permitted, expect the standard sequence of framing, plumbing, electrical, mechanical, and final inspections.
6
Rental license (if renting)
Apply for a rental license under Chapter 14 before placing tenants; remember short-term rentals under 30 days are prohibited citywide.
Permit fees and review timelines weren't published in a single ADU-specific schedule at time of writing - confirm current figures with the Planning Division at 952-563-8920, or Building and Inspections at 952-563-8930 / PlanReview@BloomingtonMN.gov for plan-review questions.
Budgeting
What it costs to build an ADU in Bloomington
Garage conversion
Roughly $65,000-$160,000, the least expensive path since the shell already exists
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
SAC fee
$2,485 per unit in 2026, charged by Metropolitan Council Environmental Services on new units that add sewer demand
City permit & plan review fees
Valuation-based under the city's published fee schedule - for example, a $150,000 project works out to roughly $1,260 in permit fee on the table on file. The city has said this schedule is being revised, so get a current, written estimate from Building and Inspections before you budget
These are general ranges from local contractor estimates and regional reporting, not quotes - Bloomington-specific cost data wasn't publicly available, so treat these as starting points, not precise figures. 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
Confirm your lot clears every threshold, not just zoning. R-1 or RS-1 zoning, at least 11,000 sq ft, and municipal sewer and water are all required - missing any one of these rules out a detached ADU.
Get your home's exact square footage before you design. The size cap is 1,000 sq ft or 33% of your primary home's four-season living area, whichever is smaller - you need an accurate baseline number before drawing plans, not after.
Ask about the mechanical-space exclusion. Up to 100 sq ft of shared mechanical or utility space can be excluded from the size calculation - worth knowing if your design is close to the cap.
Budget for a rental license if you'll lease it out. Chapter 14 requires a separate rental license, and inspections can take a few weeks to schedule - build that into your timeline.
Get a written fee estimate before you finalize your budget. The city's building permit fee schedule is being revised - call Building and Inspections for a current, project-specific number rather than relying on an old published table.
FAQ
Common questions
Do I need to live on the property to build an ADU in Bloomington?
No. Bloomington does not require owner-occupancy for ADUs.
Can I build a detached backyard ADU, or only an addition?
Both. Bloomington added detached ADUs by right in 2022 (Ordinance 2022-39), on top of its longstanding allowance for attached and internal units.
How many ADUs can I build?
One ADU per residential site, capped at 2 bedrooms.
Do I need extra parking?
There's no separate added-space requirement, but your property must continue to meet Bloomington's standard single-family parking minimums.
Which zoning districts allow ADUs?
R-1 and RS-1 districts only, on lots of at least 11,000 sq ft with municipal sewer and water service.
How much does an ADU cost to build in Bloomington?
It depends on the project type. Based on local contractor estimates and regional reporting (Bloomington-specific cost data wasn't publicly available), 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 and permit costs.
What documents do I need for the permit?
Expect to submit a site plan for Planning Division approval, floor plans and elevations of the ADU, and floor plans of the existing home so staff can confirm the 33%-of-home size calculation.
What are the city's permit and plan review fees?
Bloomington's building permit fee is based on project valuation under its published fee schedule; a $150,000 project works out to roughly $1,260 under the table on file, though the city has said this schedule is being revised. Get a current, project-specific estimate from Building and Inspections at 952-563-8930.
Can I rent my ADU out on Airbnb or a short-term rental platform?
No. Bloomington prohibits rentals of less than 30 consecutive days citywide under §14.577(b); the City Council reaffirmed this short-term rental ban in August 2024. Long-term rental (30+ days) is allowed with a rental license.
