Adu builder — Costa Mesa, CA
Last updated: September 24, 2026
What affects the price
Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.
About this service
An adu builder is a professional partner who specializes in the specific requirements of secondary housing units. You need one if you want to avoid the headache of managing subcontractors and complex permit applications yourself. We bring the expertise to keep your project on track and within code.
Frequently asked in Costa Mesa
What's the cost of an accessory dwelling unit rental in Costa Mesa?
Can I build a backyard accessory dwelling unit in Costa Mesa?
What's required for an accessory dwelling unit permit in Costa Mesa?
Is accessory dwelling unit financing available in Costa Mesa?
What does the accessory dwelling unit construction process involve?
How do I find a local ADU service in Costa Mesa?
Are there affordable accessory dwelling unit options in Costa Mesa?
Also serving nearby: Santa Ana · Huntington Beach · Westminster · Irvine · Garden Grove
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Costa Mesa — population 108,354; about 6,855 residents per square mile across 15.8 sq mi. ZIP codes covered include 92626, 92627, 92628.
Neighborhoods served in Costa Mesa: Mesa del Mar, South Coast Metro, The Heights, Upper Newport Bay, Newport Shores — and every surrounding area.
Areas we serve
Browse by state, then city.
California (3)
All of California · Costa Mesa · Jurupa Valley · Santa Maria