Questions to ask an ADU builder
What should I ask an ADU builder in San Diego?
Ask for the CSLB license number, who pulls the permit, which City fees are included, how utility and sewer connections are handled, the schedule, and the payment plan. California caps most home improvement down payments at 10% or $1,000, whichever is less. The 2026 City median single-ADU permit declared $120,900.
- What is your CSLB license number (B General Building), and is it in the business name on the quote? Check it free.
- How many ADUs have you permitted in the City of San Diego? Can I see the permit numbers?
- Who handles design, engineering, Title 24 and the permit submittal, and is it in the price?
- Which City fees do you expect for my project (school fees, capacity fees, plan check), and are they in the quote or separate?
- Does my panel need an upgrade? Have you done a load calculation? Who handles the sewer lateral and meter?
- Is solar required for my design, and is it included?
- What is the payment schedule? (California caps the down payment at 10% or $1,000, whichever is less, on most home improvement contracts.)
- Who will be on site, your crew or subcontractors? Do you carry workers' comp?
- What's your realistic timeline from permit issue to final inspection?
- What warranty do you give, and who backs the materials warranties?
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