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ADU Rules & Cost in North Dakota

A 700 sq ft detached ADU in North Dakota typically costs $146,500$239,500 ($209$342/sq ft). Here is what the rules allow.

Local zoning governs — no statewide ADU law

North Dakota ADU rules at a glance

This state has no statewide by-right ADU law, so accessory dwelling units are governed entirely by your city or county zoning code. Many cities still allow ADUs — check your local planning department for size, setback and parking rules.

Statewide law
No — local rules
Max detached size
Set locally
Guaranteed minimum
Set locally
Setback
Set locally
Owner-occupancy
Varies locally
Approval time
Set locally

Parking: Set by local ordinance — commonly 1 space per ADU unless near transit.

Estimate your North Dakota ADU

Pre-set to North Dakota. Adjust the type and size for your project.

Your property

ADU type

Estimated cost in North Dakota

$146,500 $239,500

$209$342/sq ft turnkey · midpoint $193,000

$131,300
Construction
$34,700
Design & permits
$27,000
Site work
ADU rules in North Dakota are set by your city — here's what to check.
  • iSize set locally. This state leaves ADU size limits to your city — typical caps run 600–1,200 sq ft. Check your local code.
  • iParking. Set by local ordinance — commonly 1 space per ADU unless near transit.
  • iOwner-occupancy varies. Owner-occupancy rules are set locally in this state.
  • Lot has room. A 700 sq ft ADU uses about 12% of your 6,000 sq ft lot — comfortably within typical coverage limits.

Rule basis: Local zoning governs — rules vary by city/county

If you rent it out

$1,025$1,650

est. rent/mo

8.4%

gross yield

12.8 yrs

payback

~$15,066/yr after a 7% vacancy allowance, before financing & maintenance.

Financed over 20 yrs at 7.5%, the build is about $1,555/mo — vs ~$1,350/mo in estimated rent.

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Estimates are for planning only and are based on regional construction-cost indices and published statewide ADU statutes. Local ordinances, lot conditions and contractor pricing vary — always confirm with your city planning department and a licensed contractor.

Cost by ADU type in North Dakota

ADU type600 sq ft$/sq ft
Detached new build$125,500$205,000$209$342
Attached addition$114,000$188,000$190$314
Garage conversion$68,500$125,500$114$209
Junior ADU (JADU)$57,000$102,500$95$171
Prefab / modular$102,500$171,000$171$285

ADU rules by city in North Dakota

Estimates are for planning only and are based on regional construction-cost indices and published statewide ADU statutes. Local ordinances, lot conditions and contractor pricing vary — always confirm with your city planning department and a licensed contractor.