How to Choose an ADU Builder in San Diego

1. Look for real ADU experience, not just general construction

ADUs have their own rules, setbacks, and utility challenges. A contractor who has built multiple permitted ADUs in San Diego will move faster and make fewer costly mistakes than someone treating your project as a first experiment.

• Ask how many ADUs they've built in the last 2–3 years.
• Ask where those projects were and what type (garage conversion, prefab, custom).
• Ask if you can see photos or drive by a completed ADU.

2. Understand what's included in their scope

Two bids can look very different on paper. One might include design, engineering, permits, and utilities; another might be "construction only." Before comparing price, make sure you're comparing scope.

• Who handles design, engineering, and Title 24 reports?
• Who submits to the city/county and responds to plan check comments?
• Are utility trenching and panel upgrades included?
• What allowances are included for finishes (cabinets, tile, fixtures)?

3. Compare pricing the right way

The lowest headline number isn't always the best deal. Look for clarity, transparency, and reasonable contingencies instead of just chasing the cheapest bid.

• Ask for a line-item breakdown where possible.
• Check what's marked as "allowance" vs. fixed price.
• Confirm what happens if material prices change or site surprises appear.
• Make sure you're comfortable with their payment schedule.

You can use our ADU cost calculator to see if quotes you're getting are in a realistic range for San Diego.

4. Check license, insurance, and reviews

A trustworthy ADU builder should be properly licensed and insured, and should have at least a few recent clients who are happy to talk about their experience.

• Verify their CSLB license is active and in good standing.
• Ask for proof of liability insurance and workers' comp coverage.
• Look for recent reviews that mention ADUs specifically.
• Ask for 1–2 references you can actually contact.

5. Red flags to watch out for

• Bids that are dramatically lower than everyone else with no clear reason.
• Unwillingness to put things in writing or clarify vague language.
• Pressure to skip permits or "just call it a remodel."
• Difficulty getting straight answers to basic questions about process or timeline.

6. Use a short list, not a huge list

You don't need to talk to ten different builders. For most homeowners, 2–3 serious conversations is enough to get a feel for pricing, personalities, and process.

Start by browsing our San Diego ADU builder directory. When you're ready, use the lead form on the homepage to share a few details and we can help you focus on a short, curated list.