Hiring an ADU builder in San Diego
How do I find a good ADU builder in San Diego?
Pick a builder with an active CSLB "B" general building license, recent City of San Diego ADU permits in its own name, and an itemized fixed-scope bid. In 2026 City permits, the median single ADU declared $120,900 of construction (conversions $89,600, new detached $154,300). A bid far below that should say what it leaves out.
Send one free quote request
One short form. We reply with a price range and, if you want quotes, licensed local firms. Free, no obligation.
How a request works here
We are an independent San Diego price guide, not a contractor, and we don't do the work. Send one free request. We read it ourselves and reply with a price range for your job and what to ask. If you want quotes, tell us, and we'll introduce you to licensed local firms. We check each firm's CSLB license and City permit history first. Nothing is shared with any business until you say so. No firm pays us for your request, and you never have to hire anyone.
What ADUs cost in San Diego (2026 City permits)
| ADU type | Permits | Low (25%) | Median | High (75%) |
|---|---|---|---|---|
| Garage conversion | 226 | $55,700 | $81,800 | $130,100 |
| Junior ADU (JADU) | 83 | $45,600 | $67,800 | $81,300 |
| Attached addition | 92 | $76,700 | $115,300 | $235,000 |
| New detached, 1 story | 151 | $87,700 | $125,900 | $195,200 |
| ADU above a garage | 58 | $107,700 | $162,100 | $206,900 |
| New detached, 2 story | 89 | $153,400 | $198,600 | $208,900 |
Declared construction value on City of San Diego permits issued Jan 1–Oct 15, 2026. Design, City fees, utility work and often finishes are not included, so real budgets run higher. Full tables: ADU cost guide · garage conversions · detached ADUs.
How to pick an ADU builder: 6 checks
- License. Look the firm up on cslb.ca.gov. For a full ADU you want an active B (general building) license, the $25,000 contractor bond, and workers' comp on file if they have employees. Any job of $1,000 or more needs a licensed contractor.
- San Diego ADU permits in their name. Ask for 2–3 addresses of ADUs they permitted with the City in the last two years, ideally the same type as yours. Our local firms list shows licensed firms that pulled 2026 City ADU permits.
- Design-build or separate designer. With design-build, one firm owns the drawings, the corrections and the build. With a separate architect you get more design control, but you also have to coordinate two parties. Either works. Just know who answers the City's correction letters.
- An itemized, fixed-scope bid. It should list design and engineering, City plan check and permit fees, sewer and water connections, the electrical panel or SDG&E work, solar (generally required on new detached ADUs under the California Energy Code), finishes and site work.
- A legal deposit and payment schedule. For home improvement contracts the down payment is capped at 10% or $1,000, whichever is less. Later payments should follow finished work, not dates.
- Timeline in writing. 2026 City ADU permits took a median 293 days from application to issue. Ask who handles correction rounds and how change orders are priced.
Questions to ask before you sign
- How many City of San Diego ADU permits have you pulled in the last two years? Can I see one?
- What is excluded from this price? City fees, utility connections, solar, appliances, landscaping?
- Who prepares the plans, and who answers the City's corrections?
- Do you pull the permit as the contractor? (Be careful with "owner-builder" setups.)
- What is the payment schedule, and what does each payment cover?
- How are change orders priced, and are they always written?
More: full question list · fair quote checklist · what a strong builder looks like · how the ADU permit works.
What to send for a useful quote
- Address or ZIP, and the rough lot size
- ADU type (garage conversion, detached, JADU, attached) and target square feet and bedrooms
- What is there now: garage, slab, slope, trees, side-yard or alley access
- Any plans, a designer, or a permit already in process
- Budget range and when you want to start
- Photos of the lot or garage, if you have them
Common questions
Do I need a licensed contractor to build an ADU in San Diego?
Yes for any job of $1,000 or more (labor plus materials). For a full ADU that usually means a B general building license. Check any license free at cslb.ca.gov.
How much should an ADU builder ask as a deposit?
For home improvement contracts in California, no more than 10% of the price or $1,000, whichever is less (Bus. & Prof. Code §7159). A bigger upfront demand is a red flag.
Are you an ADU builder?
No. We are an independent price guide. We reply with a price range and, if you ask, introduce you to licensed local firms. Nothing is shared until you say so, and no firm pays us for your request.