Finding the right general contractor (GC) can be a make-or-break decision for homeowners building an Accessory Dwelling Unit. In this webinar, we walk participants through the ins-and-outs of finding a GC: when and how to engage a GC, how to evaluate a bid, and red flags to watch out for. We break down the GC’s role, compare costs, and share the latest trends in ADU construction.
SOME TAKEAWAYS
When to Bring a GC into Your Project
- Ideal time: once you have a full set of construction drawings (even if not yet approved by your City)
- Engage at least 3 GCs to solicit bids
- Think about it this way: architects are great at telling you what’s possible, GCs are great at telling you how much it’s going to cost
How to Vet a GC
- Legitimate GCs carry general liability insurance, a surety bond, and often workers’ compensation coverage for their crew
- Verify license, insurance, and bonding via the California Contractors State License Board (CSLB) – https://www.cslb.ca.gov
- Look for local ADU experience — familiarity in your jurisdiction helps smooth permitting and inspections
- Ask for references — and call them
- Look for professionalism and communication in your early interactions
- Red flags: vague or overly simple bids, large upfront payments, poor communication, no references, or pressuring tactics
Reviewing Bids
- Get multiple detailed, written estimates — don’t rely on ballpark quotes – and review to make sure they’re comprehensive
- Clarify “allowances” (pre-budgeted costs) vs “exclusions” (not included in bid)
- Red flags: if one of the bids is significantly lower than the other two, take a second look – a bid that’s too good to be true probably is
Contracts: What to Look For
- Clear scope of work, fair payment schedule, and defined change order process
- Don’t be rushed into signing — take your to compare options
- Red flags: vague contracts, no mention of change orders, questionable payment schedule (avoid contracts requiring large upfront payments before work has been completed)
ADU Costs
- Bay Area ground-up ADU: ~$625/sq ft is a good conservative baseline
- Garage conversions: $250–$450/sq ft
- Cost drivers: trenching, grading, labor rates, jurisdictional fees, and supply chain issues
Bonus: ADU Contractor Market Trends: Jon Grishpul from Maxable shared a surprising stat: nearly 1 in 5 licensed California GCs received their license in the last 5 years. This shows that the market has exploded in recent years, and many contractors are inexperienced. Do your due diligence to find a contractor that has a good track record and a solid number of projects under their belt
Source: Maxable
Remember: Hiring a GC is not just about cost — it’s about trust, fit, and experience. Take your time, vet thoroughly, and get comfortable with the contractor before signing on the dotted line
