Orange County, CA

ADU Contractor in Orange County, CA

Accessory dwelling units have become one of the most popular ways for Orange County homeowners to add living space, house family, or generate rental income — and California's streamlined ADU laws have made the process faster than a standard addition. ProHome handles detached ADUs, garage conversions, attached ADUs, and JADUs throughout Orange County, from initial design through city permitting and construction.

Get a Free Estimate (949) 229-1162
CA License #1140564
4.9 Stars on Google
5 Stars on Yelp
Based in South OC
Same-Day Response
Serving Orange County Homeowners

An ADU Contractor Across Orange County

From larger-lot communities in South Orange County to tighter urban lots closer to the coast and inland cities, the right ADU approach depends heavily on your specific property — lot size, setbacks, existing structures, and any HOA guidelines all factor in. We start every project with a site assessment so the ADU we design is one your city will approve and your lot can actually support.

4.9★
Google rating across 50+ OC projects
#1140564
CSLB license — fully insured, all permits handled
Your Dedicated
Project Manager
With you from estimate to final walkthrough
What We Build

ADU Services Across Orange County

Full-scope ADU projects from design through final inspection. One licensed contractor managing architecture, permitting, and construction.

Detached ADUs

Standalone backyard units up to 1,200 sq ft, built to function as a complete home — bedroom, bathroom, kitchen, and living space. The right fit for properties with backyard space to spare.

Garage Conversions

Converting an attached or detached garage into a livable ADU — including new insulation, plumbing, electrical, and egress. Often the most practical option on tighter lots throughout Orange County.

Attached ADUs

An addition built onto the existing home with its own entrance, kitchen, and bathroom — sharing one or more walls with the main house. Often the most cost-effective way to add a self-contained living space.

Junior ADUs (JADUs)

Up to 500 sq ft, converted from existing space within the home's footprint — often a bedroom with an added kitchenette and separate entrance. The lowest-cost path to a legal second living unit.

Design & Permitting

Architectural plans, structural engineering, and submission through your city's ADU plan check process — plus HOA architectural review where applicable. California's streamlined ADU laws mean faster turnaround than a standard addition.

Site Prep & Utility Connections

Grading, utility trenching, and new or upgraded electrical, water, and sewer connections for your ADU — coordinated with the main home's existing systems so everything works together once construction wraps.

Why ProHome

What Makes Us Different

Orange County homeowners have plenty of contractor options. Here's what consistently sets us apart.

4.9 Stars

Google Rating — Earned Project by Project

Our rating reflects clear scopes, honest pricing, and follow-through. Homeowners who hire us know where their project is at all times — we reach out before they have to ask.

CSLB #1140564

Licensed, Insured, Permitted — Every Time

We manage the full ADU plan check and permitting process with your city, including structural, electrical, plumbing, and utility approvals, and coordinate every inspection — plus HOA submissions where required.

South OC

Local and Close By

Based in Lake Forest, we've built ADUs across Orange County's cities and know how each jurisdiction's plan check process and design standards differ.

Communication

You'll hear from us before you have to ask.

No chasing us down for a status update. You get a named point of contact and regular check-ins throughout your project. Calls returned the same day. That's not a promise on paper; it's how every job runs.

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Common Questions

ADU Contractor FAQ — Orange County, CA

What Orange County homeowners typically ask before starting an ADU project.

What are California's ADU rules for Orange County homeowners?
California's statewide ADU laws require cities to approve qualifying ADUs through a streamlined, ministerial process — meaning faster review than a standard addition, with limits on how much cities can restrict size, parking requirements, and owner-occupancy. Individual Orange County cities still have local standards for setbacks, height, and design that affect what's possible on a given lot, which is why we start with a site-specific assessment rather than a one-size-fits-all plan.
How big can an ADU be?
Under California's statewide ADU rules, detached ADUs can generally be built up to 1,200 sq ft, attached ADUs up to 50% of the existing home's square footage (with some caps), and JADUs up to 500 sq ft. Lot size, setbacks, and lot coverage limits also factor in — we'll work through what's realistic for your specific property during the design phase.
How long does an ADU project take from start to finish?
Design and permitting typically takes 2 to 4 months, depending on plan complexity and your city's review timelines — California's ADU laws require faster turnaround than standard permits. Construction generally runs 4 to 8 months for a detached ADU, or 6 to 10 weeks for a garage conversion or JADU.
What does an ADU cost in Orange County?
A detached ADU typically runs $150,000 to $300,000+ depending on size and finish level. Garage conversions generally run $60,000 to $120,000, and JADUs run $40,000 to $80,000. We provide a full written quote — including design, permitting, and construction — after an on-site walkthrough.
Do I need separate utility meters for an ADU?
It depends on the project and your plans for the unit. Many ADUs share the main home's utility connections with sub-panels and sub-metering, while some homeowners — especially those planning to rent the unit — opt for separate utility meters. We'll go over the tradeoffs and what each option involves during design.
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ProHome handles every trade in-house.

ADU Contractor by City

Find Your City

City-specific ADU guides for Orange County.

Orange County, CA

Ready to Start Your ADU Project?

Call us today or request a free on-site estimate. Detailed scope, transparent pricing, no pressure.

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Licensed & Insured — CSLB #1140564
4.9 Stars on Google
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