Hiring for a garage conversion is different from hiring for a remodel

A garage-to-ADU conversion is not a simple interior renovation. It touches framing, plumbing, electrical, HVAC, and finishes, and it needs a building permit. State law gives the agency 60 days to decide a completed application. That is a decision deadline, not a total-project average. Unpermitted work is a resale and occupancy problem.

The contractor you hire is your permit agent, trade coordinator, and the name on the home-improvement contract. Published market bands on this site for a full ADU conversion are $75,000-$150,000 including permits and trades. A junior ADU conversion is listed at $50,000-$90,000. Those are market ranges, not a quote from Garage Convert SD. There is no honest single calendar from first call to occupancy. State law gives the agency 60 days to decide a completed application. Construction time is set by the licensed pro after permits issue.

Here is how to hire correctly.

Start with license verification

California requires a contractor’s license for any project over $500 in labor and materials. For a garage conversion, you want a General Building Contractor (B license) or, if the contractor is doing specialty trade work themselves, the appropriate specialty license (C-20 for HVAC, C-36 for plumbing, C-10 for electrical).

Verify every contractor’s license at cslb.ca.gov before any conversation about money or signing anything. Check three things:

Active license status. The license must show as active. A recently expired or suspended license is a disqualifying finding, not a minor issue.

Workers’ compensation insurance. If the license shows “exempt” for workers’ comp, the contractor works alone with no employees and should not be bringing on subcontractors under their license. Most garage conversion contractors carry workers’ comp because they have employees or regular subcontractors. Ask for a certificate of insurance.

Complaint and discipline history. The CSLB license lookup shows disciplinary history. One nuanced complaint from years ago may be less significant than multiple recent complaints.

What to ask about ADU and garage conversion experience

Not every contractor with a B license has done ADU conversions in San Diego. This is a specific type of project with specific permit pathways, and experience matters.

Ask directly:

“How many garage conversions to ADUs have you completed in San Diego County in the last three years?”

Ask how they handle incomplete applications, because the 60-day state decision clock starts only when the agency treats the packet as complete.

“Have you permitted projects in [your specific city]?”

City of San Diego, other incorporated cities, and unincorporated County land use different counters. A crew that has pulled permits in your jurisdiction can explain that counter’s current intake, not a countywide wait-time rumor.

“What is your typical plan check timeline for a project like mine?”

Treat any calendar as the contractor’s experience, not a published city guarantee. The legal clock is 60 days from a completed application. It is a decision deadline, not an approval or a build schedule.

“Do you handle the permit process yourself or do you use a permit expediter?”

Both approaches are valid. A contractor who does permit expediting in-house tends to have tighter feedback loops. One who uses an expediter may still have good results if the expediter is experienced.

Insurance requirements

Before signing a contract, get certificates of insurance for two policies:

General liability insurance. This protects you from property damage and bodily injury claims arising from the contractor’s work on your property. Ask for a current certificate and whether you can be named as an additional insured. Do not accept a spoken coverage amount. Read the certificate.

Workers’ compensation insurance. This covers injuries to the contractor’s employees or subcontractors while working on your property. Without it, an injured worker can potentially make a claim against your homeowner’s policy. Ask for a certificate showing current coverage.

If the contractor says they do not carry one of these policies, that is a hard stop. Do not proceed.

How to compare quotes

Get three written quotes minimum. Comparing garage conversion quotes requires more than looking at the bottom line.

Scope of work. The most useful comparison is whether each quote covers the same scope. If one quote includes permit fees and two do not, you are not comparing the same thing. If one quote includes the subfloor and two describe it as a line item “TBD,” you will have a surprise.

Ask every contractor to include the permit and plan check fees (even if estimated), subfloor system, window and door work, insulation, HVAC (system and installation), electrical (panel upgrade if needed, plus circuits), plumbing, drywall, paint, and finishes as separate line items. Then compare line by line.

Product specifics. If one contractor is spec’ing a Mitsubishi mini-split and another is quoting a no-name brand, that is a real difference. Ask for the manufacturer and model on HVAC, windows, and any other major equipment.

Permit and inspection handling. Confirm that the quote includes the contractor pulling the permit in their name, coordinating all inspections, and managing the certificate of occupancy process.

Payment schedule. For a covered home-improvement contract, California caps the downpayment at $1,000 or 10 percent of the contract price, whichever is less. Later payments should be tied to described work in the written contract, not to a verbal percentage. Change orders join the contract only when both parties write and sign them.

Red flags to recognize

No written contract. Everything should be in writing. A verbal agreement is not a contract for a project of this size.

Permit described as optional. Any contractor who suggests you can skip the permit and have it added later, or who implies the city won’t find out, is telling you to expose yourself to significant legal and financial risk.

The quote is dramatically lower than others. A much lower bid often means missing scope or unlicensed labor. Compare the same line items before you treat the bottom line as a savings.

Cannot provide references from completed San Diego ADU projects. Ask for three references with contact information and call them. Ask specifically about permit timeline accuracy, communication during the project, and whether the final cost matched the quote.

Pressure to sign quickly. A legitimate contractor does not need you to sign today. If there is pressure to commit before you have checked the license, reviewed insurance, and compared bids, that pressure is itself a signal.

Using a referral service

Garage Convert SD connects San Diego homeowners with licensed, independent local professionals who do garage conversions. We are a referral service, not a contractor. You verify the license at cslb.ca.gov, compare written quotes, and make the hiring decision. Our number is (858) 400-4935.

More information is on the garage conversion service page. Verify any contractor’s license at cslb.ca.gov before signing a contract.

What license does a garage conversion contractor need in California?

A B (General Building) license is the most common. Contractors doing specialty trade work themselves (plumbing, electrical, HVAC) need the corresponding C license for those trades or must use licensed subcontractors.

Can a contractor without a license do a garage ADU conversion in California?

No. California law requires a contractor’s license for any project over $500. A contractor without a valid CSLB license cannot legally pull permits, which means the work cannot be inspected or certified as code-compliant. This exposes you to both financial and legal risk.

How much should a deposit be for a garage conversion in San Diego?

California law generally limits contractor deposits for home improvement contracts to 10% of the contract price or $1,000, whichever is less. Any larger first payment should be a written progress payment tied to described work, not a spoken exception.

Should I get a fixed-price or cost-plus contract for a garage conversion?

Fixed-price (lump-sum) contracts are generally better for homeowners because they define the total cost upfront and put the risk of cost overruns on the contractor. Cost-plus contracts are common for renovations with high uncertainty, but garage conversions are well-defined enough that a fixed price with a defined change order process is the standard and preferred approach.

To get connected with licensed independent local crews, see our design consultation service page.