ADU Construction in Los Alamitos, CA

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ADU Builder

ADU Construction in Los Alamitos, CA

Serhal Builders builds ADUs in Los Alamitos, including detached backyard units, garage conversions, attached ADUs and junior ADUs. Our office is in Fullerton, a short drive away.

Los Alamitos updated its ADU rules in December 2025 (Ordinance No. 2025-13, Municipal Code Section 17.28.020) to line up with state law. Complete applications are reviewed ministerially by the city’s Development Services Director, without a public hearing.

We’re a licensed, veteran-owned general contractor (CSLB #1074208) with more than 31 years in construction, and we’ve built ADUs throughout northern Orange County.

Full-Service Solutions

Complete ADU Services in Los Alamitos

One licensed contractor from design and permits to the final inspection.

Detached ADUs icon
Detached ADUs

A separate backyard home built from the ground up, with its own entrance, kitchen and bathroom.

Garage Conversions icon
Garage Conversions

We turn an existing garage into a full living space, often the most budget-friendly way to add a unit.

Attached ADUs icon
Attached ADUs

An addition connected to your home with its own entry, kitchen and bath, so family stays close but independent.

Junior ADUs (JADU) icon
Junior ADUs (JADU)

A unit of up to 500 square feet created inside your existing home, with its own entrance.

Design & Floor Plans icon
Design & Floor Plans

In-house design, plans from our design partner, or your own architect’s plans. We work whichever way suits you.

Permits & City Approval icon
Permits & City Approval

We prepare and submit the permit package and handle plan-check corrections with the city.

Utilities & Systems icon
Utilities & Systems

Electrical, plumbing, sewer, water and gas tie-ins planned early so there are no surprises mid-build.

Kitchens, Baths & Finishes icon
Kitchens, Baths & Finishes

Cabinets, counters, tile, flooring and fixtures, all handled by the same team that remodels full homes.

Why Choose Us

Solutions & Benefits

Every lot is different. These are the three ways most homeowners add a unit.

Detached ADU
Attached & JADU
Plans & Permits

Detached ADUs & Garage Conversions

A detached ADU gives you a separate backyard home with its own entry, kitchen and bath. A garage conversion reuses an existing structure and is often the most budget-friendly way to add a unit.

Attached ADUs & Junior ADUs

An attached ADU connects to your home but lives independently. A junior ADU is up to 500 square feet created inside your existing home, a good fit for family members who want their own space nearby.

Plans & Permits Your Way

Use our in-house design, our design partner, or plans you already have. We prepare the permit package, respond to plan-check comments and coordinate inspections until final sign-off.

Local Knowledge

What Los Alamitos Homeowners Should Know

2025 ordinance – Adopted December 15, 2025, to bring local ADU rules in line with state law.
What a single-family lot can have – One attached or converted ADU, one junior ADU and one detached new-construction ADU.
Size and height – Junior ADUs must be 220 to 500 square feet, and detached ADUs are generally limited to 16 feet in height, with some exceptions.
Fees – No impact fee applies to ADUs under 750 square feet.
ADU floor plans for a Los Alamitos home
Homeowners reviewing ADU floor plans
Simple Process

Our Working Process

Building an ADU in Los Alamitos has more steps than a remodel. Our process keeps it clear and manageable.

We look at your lot, utilities and goals and recommend the ADU type that fits.
We design in-house, with our partner, or from your plans, then handle submittal and plan-check corrections with the city.
Our crew builds the ADU and coordinates every inspection through to final sign-off.
Quick Answers

Frequently Asked Questions

Are ADUs allowed in Los Alamitos?

Yes. Los Alamitos allows ADUs and junior ADUs under its local code and California ADU law. Your lot, utilities and any easements decide which type and size work best.

Do I need a public hearing for an ADU in Los Alamitos?

No. Under the city's 2025 ordinance, complete applications are reviewed ministerially by the Development Services Director, without discretionary review or a public hearing.

Can I rent out an ADU in Los Alamitos?

Yes, for stays longer than 30 days. Short-term rentals of 30 days or less are prohibited, and an ADU can't be sold separately from the main home.

Are you a licensed contractor?
Yes. Serhal Builders is a licensed California general contractor (CSLB #1074208). We're veteran-owned and family-run, with more than 31 years of construction experience.
Do you handle the plans and permits?
Yes. We can design your ADU in-house, work with our design partner, or build from plans you already have. Either way we prepare the permit package and handle corrections with the city.
Can I convert my garage into an ADU?
In most cases, yes. California law generally does not allow cities to require replacement parking when a garage is converted into an ADU. We check your specific property before design.
How do I get started?
Call us at 949-829-4999 or request a quote online. We'll talk through your goals, look at your property and explain which ADU type fits best.