Quick, all-in budget range for a new ADU in any location worldwide. Not a quote – a smart starting point for feasibility, using national contractor pricing adjusted to your local cost level.
This tool gives an educational rough budget range only, based on typical national all-in ADU costs (design, permits, site work, utilities, construction) adjusted to your local cost level. Actual pricing requires a full feasibility review.
Calculate the cost of building an Accessory Dwelling Unit (ADU) in California. Estimates include permits, construction, utilities, and finishing costs.
An Accessory Dwelling Unit is a secondary housing unit on a single-family residential lot. It can be attached, detached, or a garage conversion.
ADU costs typically range from $100,000 for a garage conversion to $400,000+ for a new detached unit, depending on size and finishes.
Yes, ADUs require building permits, electrical permits, plumbing permits, and sometimes mechanical permits depending on the scope.
Typically 3-6 months for construction after permits are approved, which can take 2-4 months.
Our Network
Built by Cali Dream Construction · CSLB #1054602
Need a custom calculator for your trade business? We'll get back to you within 24 hours.