ADU Builders & Contractors in Montclair, CA

With 77 verified ADU contractors serving Montclair, CA, homeowners have plenty of options for their accessory dwelling unit project. Local contractors ready to help specialize in everything from design-build to permit navigation.

📊 ADU Quick Facts for Montclair

Avg. Cost/sqft

$207-$382

Permit Timeline

60-120 weeks

Max Size

1200 sqft

Setbacks

4ft sides

Top 77 ADU Contractors in Montclair

🏗️

Montclair, CA

Frontline Enterprise — licensed ADU contractor in Montclair, CA. Detached ADU construction. 33+ years experience.

🏗️

Montclair, CA

Boice David Karl — licensed ADU contractor in Montclair, CA. Detached ADU construction. 7+ years experience.

🏗️

Montclair, CA

Sandoval Construction & Home Improvements — licensed ADU contractor in Montclair, CA. Detached ADU construction. 21+ years experience.

🏗️

Montclair, CA

Gonzalez Cristian — licensed ADU contractor in Montclair, CA. Detached ADU construction. 10+ years experience.

🏗️

Montclair, CA

Specialty Trades Inc — licensed ADU contractor in Montclair, CA. Detached ADU construction.

🏗️

Montclair, CA

J A Floor Coverings Inc — licensed ADU contractor in Montclair, CA. Detached ADU construction. 25+ years experience.

🏗️

Montclair, CA

Slater Waterproofing Inc — licensed ADU contractor in Montclair, CA. Detached ADU construction. 46+ years experience.

🏗️

Montclair, CA

H L M Inc — licensed ADU contractor in Montclair, CA. Detached ADU construction. 15+ years experience.

🏗️

Montclair, CA

Master Craft Builders Inc — licensed ADU contractor in Montclair, CA. Detached ADU construction.

🏗️

Montclair, CA

Torres Wilfredo — licensed ADU contractor in Montclair, CA. Detached ADU construction. 22+ years experience.

💰 How Much Does an ADU Cost in Montclair?

Garage Conversion

$73,500 - $133,500

Converting existing garage to living space

Detached ADU

$157,000 - $332,000

New standalone unit (600-1,200 sqft)

Permit & Fees

$1,111 - $5,111

Plan check, permits, utility connections

* Costs vary based on size, finishes, site conditions, and contractor. Get quotes from multiple Montclair contractors to compare pricing.

❓ Frequently Asked Questions About ADUs in Montclair

How much does it cost to build an ADU in Montclair?
The average cost to build an ADU in Montclair ranges from $157,000 to $332,000, or approximately $207 to $382 per square foot. Garage conversions typically cost $73,500 to $133,500.
How long does it take to get an ADU permit in Montclair?
The ADU permit process in Montclair typically takes 60 to 120 weeks. California law requires cities to approve or deny ADU permits within 60 days of receiving a complete application.
What are the ADU size limits in Montclair?
In Montclair, detached ADUs can be up to 1200 square feet. Attached ADUs are limited to 50% of the primary dwelling or 1,200 sqft, whichever is less. Junior ADUs (JADUs) are limited to 500 sqft and must be within the existing home.
What is the setback requirement for ADUs in Montclair?
Montclair requires 4-foot setbacks from side property lines and 4-foot setbacks from rear property lines for new ADU construction. Converted structures (like existing garages) may maintain their current setbacks.
Do I need to provide parking for my ADU in Montclair?
No parking is required for ADUs in Montclair if your property is within half a mile of public transit, in a historic district, part of an existing multi-family building, or if the ADU is a garage conversion. Otherwise, one space may be required.

Also See ADU Contractors In

Ready to Build Your ADU in Montclair?

Get free quotes from top-rated local contractors

Find Contractors Now