Garage Construction & ADUs Cost Guide — Portland, ME

Verified 2025 pricing for garage construction & adus services in Portland. Updated quarterly from local contractor data.

Service Cost Ranges

Service	Low	Average	High	Unit
Detached Garage Construction	$23,000	$51,750	$115,000	per project
ADU / Garage Apartment	$69,000	$138,000	$287,500	per project
Carport Installation	$4,600	$10,350	$28,750	installed

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Older housing stock (pre-1942) increases complexity and materials cost

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✓Ask about seasonal discounts

✓Bundle multiple services

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