Build a realistic early-stage budget for a detached accessory dwelling unit in the greater Seattle area. The estimate shows a range because property conditions—not just square footage—can significantly affect the final cost.
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This takes about one minute. No contact information is required.
The model uses adjustable regional construction ranges plus planning, engineering, permitting, site, utility, demolition, and contingency allowances. It is intended for early planning—not bidding, lending, appraisal, or construction contracting.