How much does an ADU cost
in Los Angeles?

In 2026, a new detached ADU in Los Angeles typically costs $300–$550 per square foot all-in (design, permits, construction, and finishes). That puts a 600 sqft one-bedroom at roughly $180,000–$330,000 and a 1,200 sqft three-bedroom at $360,000–$660,000. CALI ADU Signature Homes fall at the low-to-mid end of this range with premium finishes included, because pre-designed plans eliminate custom architecture costs and our volume of projects reduces per-unit construction costs.

Garage conversions typically cost 30–50% less than new detached construction because the foundation and framing already exist. A typical garage conversion runs $150–$300 per square foot. However, existing garages often have structural limitations, low ceiling heights, and moisture issues that add unplanned cost. New construction costs more upfront but gives you a purpose-built home with no compromises.

It depends on who's quoting. Many contractors quote construction cost only — which excludes design, engineering, permits, appliances, and site work. Always ask what's included. Our estimated cost to build covers construction, finishes, appliances, and fixtures. Design, engineering, and permit processing are covered by the fixed plan price. City fees are paid at cost.

City permit fees for an ADU typically range from $5,000 to $15,000 depending on the size and your jurisdiction. This includes plan check fees, building permit fees, and school impact fees. Utility connection fees (water, power + gas) add another $3,000–$8,000. These fees are set by the city and utility companies, not the builder.

Because most ADU builders use a cost-plus model — they estimate the work, start building, and adjust the price as surprises appear. Lot conditions, permit delays, design changes, and subcontractor pricing all introduce variability. Our plans have been built before, so the estimates come from real projects, not guesses.