One licensed contractor to plan, permit and build your ADU.
An accessory dwelling unit (ADU) is a second, smaller home on your property, with its own kitchen, bathroom and entrance. Homeowners build them for aging parents, adult kids, guests, a home office, or rental income.
Serhal Builders builds ADUs across Orange, Riverside and San Diego Counties. We’re a licensed California general contractor (CSLB #1074208) based in Fullerton, with more than 31 years of construction experience. We handle the whole job, from the first site visit to the final inspection, so you have one team to call.
Call 949-829-4999 | Request an ADU Consultation
Types of ADUs We Build
Detached ADU
A separate small home in your backyard. It gives the most privacy for whoever lives there, and it doesn’t change the main house.
Garage Conversion ADU
We turn an existing garage into a full living space. Because the walls, roof and slab are already there, a conversion is often the most direct way to add a unit.
Attached ADU
An addition built onto your home with its own entrance, kitchen and bathroom. It keeps the yard open while adding a separate unit.
Junior ADU (JADU)
A smaller unit of up to 500 square feet created inside your existing home, for example from a bedroom suite. It’s a good fit when you want a separate space without building outward.
Plans and Permits, Your Way
Every ADU starts with plans and a city permit. Depending on your project, we can:
- Take care of design, plans and permits for you, working with the design professionals we trust;
- Build from plans you already have; or
- Step in partway, if you’ve started the process and need a builder to take it from here.
Either way, we review the plans against your property, your city’s rules and your budget before construction starts, so there are fewer surprises once the work begins.
How Your ADU Project Works
- Site visit. We walk your property, talk through how you want to use the ADU, and check what’s practical for your lot.
- Plans and permits. Plans are drawn or reviewed, submitted to your city, and revised until approved.
- Written quote. You get a written price and scope based on the approved plans.
- Construction. Our team builds the unit, from foundation, framing and utilities to finishes, and keeps you updated along the way.
- Final inspection. We schedule the city inspections and walk the finished ADU with you.
Why Homeowners Choose Serhal Builders
- Licensed California general contractor, CSLB #1074208
- More than 31 years of construction experience
- Family-run and veteran-owned, based in Fullerton
- Kitchens, bathrooms, plumbing, electrical, flooring and drywall all handled by one team
ADU Questions
Can I build an ADU on my property?
California law allows ADUs on most residential lots, but size, height and placement rules vary by city and by lot. We check your city’s rules and your property during the site visit.
Do I have to live on the property to rent out an ADU?
Under current California law, cities can’t require the owner to live on the property for an ADU. Junior ADUs that share a bathroom with the main house are different. We’ll go over what applies to your project.
How much does an ADU cost and how long does it take?
It depends on the type of ADU, its size, your lot, your city’s requirements and the finishes you choose. After the site visit and plans, you get a written quote and schedule for your specific project.
Which areas do you serve?
We build ADUs throughout Orange, Riverside and San Diego Counties, from our shop at 1328 E Orangethorpe Ave in Fullerton.
Start Your ADU
Tell us about your property and what you want the ADU for, and we’ll set up a site visit.