– ADU Contractor
– Garage Conversions


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Orange County Construction Owner Keith Daigneault

What Makes Us a Professional ADU Contractor in O.C.?

Hello, my name is Keith Daigneault, the owner of Orange County Construction, an ADU company and we specialize in building ADUs along with JADUs, Garage Conversions & Room Additions.

When you contact us for a FREE ADU ESTIMATE, Keith will be the person to call you, then come visit your project to get all info needed for your new ADU project and finally send you a completely itemized, written estimate. When hiring an ADU company it’s important to make sure they have built several ADUs, and fully understand the permit process and state guidelines.

As an ADU Company, we approach every ADU whether attached or detached as a custom project. We will design your ADU and create the design plans and get the ADU permits for you. We-Do-It-All. Orange County Construction ADU Contractor has beautiful completed ADU project all over North OC. We just finished two in Costa Mesa, one detached in the city of Orange, one attached ADU in Huntington Beach, and a few garage conversion ADUs in several areas. We offer our affordable ADU services in Anaheim, Buena Park, Costa Mesa, Cypress, Fountain Valley, Fullerton, Garden Grove, Huntington Beach, Irvine, La Palma, Lake Forest, Los Alamitos, Midway City, Newport Beach, Orange, Santa Ana, Seal Beach, Stanton, Sunset Beach, Surfside, Tustin, Westminster, Yorba Linda, and Rossmoor, CA.

Visit our ADU Frequently Asked Questions page for lots of great info about AUDs.

Custom Built ADU in Orange County, CA.

Completed ADU build in Orange County, CA

This ADU was designed and built to accommodate a client’s daughter with special needs. My client did all the interior decoration and design of the ADU which is a free-standing, 700 sq ft ADU.

This backyard ADU has two bedrooms, a nice bathroom, a great room consisting of a living room, dining room table, kitchen and stackable laundry room.


As a trusted and local ADU Contractor in Orange County, we cater to building and remodeling homes for our clients. As an ADU Company, we start with your free estimate and offer you a guaranteed price in writing for your ADU. Once hired we start the ADU plans and follow with getting a permit from the City Building department for your new ADU.


Custom ADU build in city of Orange, CA by ADU Contractor, Orange County Construction

Another Beautiful ADU Design & Build by
Orange County Construction ADU Contractor


We are a very experienced Design/Build company that can offer accurate pricing up-front before spending money on plans.

We Love Building ADUs

We do the complete design and build for you using the best materials and sub-contractors in the Orange County today!

You Enjoy Your New ADU

We will finish your ADU project on time and on budget allowing you to enjoy it for many years while adding value to your home.


Accessory Dwelling Units
Construction Process

ADU Construction

ADU company

ADU Design Plans


Photos Of Some Recent ADU Projects in OC


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ADUs & Garage Conversion Common Questions

Why are they called "ADUs?

ADU stands for “Accessory Dwelling Unit” and the JADU is a “Junior ADU”. The name ADU is the official name the State of California gave when they mandated that all cities must allow them to be built. It’s also another name for “grandma unit” or “guest house” and more.

-click here for all ADU rules

What is a Garage Conversion?

That is when you convert your two car garage to a small living space or a JADU. It will need to be at least a two car garage or larger.

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What does an ADU need to include?

Every ADU needs to have a minimum of a kitchen with a fridge, range (or cook-top), cabinets for storage, sink and a certain amount of countertop space for food preparations. It also requires a hood and fan with ducting to the outside for the kitchen. Then you also need a full bathroom (tub or shower or both) and a sleeping area of no less than 7′ x 7′.

-click here for all ADU rules

Will my city allow me to build an ADU?

The short answer is “YES”, as long as you adhere to both the state and city requirements. If you do, then the City cannot deny you a permit. This is where we can help you, we know the laws.

-click here for all ADU rules

Does my ADU need to be detached?

You can do either, attached or detached. If it’s attached to your home, you have to have a separate entrance for the ADU and no access from the house into the ADU. You can also convert your garage to an ADU.

-click here for all ADU rules

What is a JADU?

Basically a JADU is the same as an ADU but it’s limited to 500 square feet or less. Most of the time they are built in small backyards or as a garage conversion.

-click here for all ADU rules

Why Choose Us

We are setting industry standards for “Customer Service”


Very detailed contracts


Transparent communication


We do what we say


Remodeling homes in OC since 1985 - Plenty of references

ADU kitchen designs

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