AGrannio

Can You Build an ADU in Auburn?

Yes — Auburn is governed by Maine's statewide ADU law, which limits what the city can restrict. A 700 sq ft detached ADU here runs about $157,000–$257,000.

Construction costs in Auburn track close to the Maine state average.

Detached ADU (700 sq ft)

$157,000–$257,000

Garage conversion (400 sq ft)

$49,000–$90,000

Statewide protection

Yes

What applies in Auburn

Maine's statewide standard (30-A M.R.S. §4364-B (LD 2003, 2022)) is the starting point, but parcel-level rules, fees and design review are set locally. Confirm those details with Auburn before design.

Estimate your Auburn ADU cost

Your property

ADU type

Estimated cost in Maine

$157,000 – $257,000

≈ $224–$367/sq ft turnkey · midpoint $207,000

$140,700
Construction
$37,300
Design & permits
$29,000
Site work
Good news — building an ADU in Maine is very likely allowed.
  • iSize set locally. This state leaves ADU size limits to your city — typical caps run 600–1,200 sq ft. Check your local code.
  • ✓No extra parking likely required. Set by local ordinance — commonly 1 space per ADU unless near transit.
  • ✓No owner-occupancy requirement. You can rent out both the main home and the ADU — you do not have to live on the property.
  • ✓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: 30-A M.R.S. §4364-B (LD 2003, 2022)

If you rent it out

$1,100–$1,775

est. rent/mo

8.4%

gross yield

12.8 yrs

payback

~$16,182/yr after a 7% vacancy allowance, before financing & maintenance.

Financed over 20 yrs at 7.5%, the build is about $1,668/mo — vs ~$1,450/mo in estimated rent.

Get your detailed feasibility report →

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.

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Other Maine cities

PortlandLewistonBangorSouth Portland

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.