How to Choose an ADU Builder: 10 Questions to Ask Before Hiring

Jaime Costilla ·

How to Choose the Right ADU Builder

Choosing the wrong ADU builder can cost you thousands in overruns and months in delays. Vision ADU was founded in 2018; founders Barak and Jaime bring 30+ years of combined residential construction experience.

Here are the 10 questions you must ask before hiring anyone.

Question 1: Are You Licensed and Insured?

This seems obvious, but many homeowners skip verification. In California, your ADU builder needs:

  • Active California Contractor's License (B - General Building)
  • Workers' Compensation Insurance
  • General Liability Insurance (minimum $1 million)
  • Bond (as required by the CSLB)

How to verify: Check the California Contractors State License Board website. Enter the license number and verify it's active with no complaints.

Vision ADU holds California License #1115842 -- you can verify us anytime.

Question 2: How Many ADUs Have You Built?

ADU construction has specific challenges that general contractors may not understand. An experienced ADU builder knows:

  • City-specific permitting quirks across different jurisdictions (see our LA permit process guide)
  • How to maximize square footage within setback requirements
  • Common engineering challenges with residential lots
  • Title 24 energy compliance requirements for ADUs
  • How to handle utility connections efficiently

The Vision ADU team has completed over 75 ADUs across its service area. Read our client's experience: Buck's ADU journey in Granada Hills.

Question 3: Do You Handle Permits or Do I?

This is a critical question. The permitting process is complex and varies by city. A quality ADU builder handles:

  • Architectural plans and engineering
  • Title 24 energy calculations
  • City permit application submission
  • Plan check corrections and resubmissions
  • All inspections during construction
  • Final sign-off and certificate of occupancy

If a builder tells you to handle your own permits, walk away. They either lack experience or are trying to avoid accountability.

Question 4: Can I Visit a Completed Project?

Any reputable builder should be able to show you completed work. Better yet, ask to speak with a recent client. At Vision ADU, we invite homeowners to visit our Anaheim showroom where you can see finishes, materials, and completed ADU layouts in person.

Question 5: What's Included in Your Quote?

Get a detailed, itemized quote. Beware of vague line items or "allowances." Your quote should clearly include:

  • Design and architecture fees
  • Permit fees and city charges
  • All construction labor and materials
  • Fixtures, appliances, and finishes
  • Utility connections
  • Cleanup and landscaping restoration
  • Timeline milestones

Question 6: What's Your Payment Schedule?

A legitimate builder follows a reasonable payment schedule tied to project milestones -- never all upfront. In California, contractors cannot legally charge more than $1,000 or 10% of the contract price (whichever is less) as a down payment.

Question 7: What Warranties Do You Offer?

Ask about both workmanship and product warranties:

  • Workmanship warranty: How long does the builder guarantee their labor?
  • Product warranties: Are appliances, fixtures, and materials covered?
  • Structural warranty: Is the foundation and framing warranted?

Vision ADU provides the longest labor warranties in the industry, lifetime product warranties, and completion guarantees.

Question 8: How Do You Handle Changes and Surprises?

Every construction project has unexpected issues -- hidden plumbing, soil conditions, or design changes. Ask:

  • How are change orders handled and documented?
  • Who approves changes before work proceeds?
  • How are cost overruns communicated?

A transparent builder documents everything in writing before proceeding with any change.

Question 9: What's Your Realistic Timeline?

Be skeptical of any builder who promises unrealistically fast timelines. A typical ADU project takes:

  • Design and permits: 8-16 weeks (varies significantly by city)
  • Construction: 3-6 months depending on size and complexity
  • Total: 6-10 months from start to move-in

Read our detailed guide on how long it takes to build an ADU.

Question 10: Do You Specialize in ADUs?

A general contractor who occasionally builds ADUs is very different from a dedicated ADU builder. ADU specialists:

  • Know every city's specific ADU ordinances
  • Have established relationships with plan checkers
  • Understand the unique design constraints of accessory dwelling units
  • Can advise on rental optimization and ROI
  • Stay current with rapidly changing California ADU laws

Red Flags to Watch For

  • No physical office or showroom
  • Won't provide references or show completed work
  • Pressures you to sign quickly
  • Asks for large upfront payment
  • Can't explain the permit process for your specific city
  • License complaints on the CSLB website
  • No written contract

Make the right choice. Visit our Anaheim showroom to see our quality firsthand and get a free, detailed estimate for your ADU project.

Before you start, familiarize yourself with California's ADU laws, understand how much an ADU costs, and avoid the biggest ADU mistakes homeowners make.

Choosing a builder is the most important decision in your ADU journey. Book a free consultation with Vision ADU — our team has completed over 75 ADUs across its service area.

Free consultation