How to Choose an ADU Contractor

The contractor decision carries more variance than any other choice in your project — the same plans, built by different GCs, produce different buildings, budgets, and years of your life. Here's the vetting funnel that loads the dice.

Stage 1: Build a real long list (4–6 candidates). Sources in order of signal quality: recent ADU clients in your area you can actually talk to; your designer's build-side referrals (they know who executes their plans well); local ADU projects you can see. Weakest signal: ads and lead-gen sites, where the best marketers — not the best builders — surface.

Stage 2: The paper cut (takes one evening). Eliminate anyone who fails: active B (General Building) license verified at the CSLB website (lesson 11.5 walks through it); bonded; carries liability insurance and workers' comp (ask for certificates — uninsured workers on your property are your financial problem); and a physical business presence you can find. This stage costs candidates nothing to pass — which is exactly why failing it is disqualifying.

Stage 3: The ADU interview. Seven questions, in order of revelation:

1. How many ADUs have you completed in the last three years? (ADUs are a specialty — small-lot logistics, occupied-site work, ADU-specific inspections.)
2. May I see two of them and speak to the owners?
3. Who runs my site day-to-day, and how many projects will they carry simultaneously? (You're hiring the superintendent as much as the company.)
4. Walk me through your payment schedule. (Lesson 11.10 gives you the answer key.)
5. How do you price and process change orders? (Lesson 11.9's answer key.)
6. What's your current backlog — when could you actually start? (Honest answers here predict honest everything.)
7. What does your warranty cover, and who answers the phone in year two?

Stage 4: References — but ask the right questions. Everyone's references are their happy clients, so extract signal anyway: What went wrong, and how did they handle it? (Something always goes wrong; the handling is the data.) How close was the final cost to the contract? Would you use them again tomorrow? — and listen for the pause.

Stage 5: Bids from your finalists (2–3). Normalize and compare per Module 6.10 and lesson 11.8. Then decide on the whole picture: normalized price, communication quality during bidding (it only degrades after signing), reference warmth, and start-date honesty.

The meta-rule: every stage where a contractor is slow, vague, or annoyed during courtship predicts the marriage. Bidding-phase behavior is the best behavior you will ever see.