Adu quote — 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 quote is a detailed breakdown of the costs to build your secondary unit, including site preparation, materials, and labor. Factors like foundation type, utility trenching distance, and interior finish levels will move your total up or down. It provides the financial roadmap for your project. Exact pricing confirmed free on the call.
Frequently asked in Costa Mesa
What is the best accessory dwelling unit for Costa Mesa?
Are there ADU rules for Massachusetts in Costa Mesa?
How do I get an ADU estimate in Costa Mesa?
What is the accessory dwelling unit construction cost in Costa Mesa?
Where can I find an accessory dwelling unit for rent in Costa Mesa?
What is an affordable accessory dwelling unit in Costa Mesa?
What is a backyard accessory dwelling unit 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, Westside, Eastside, The Triangle — and every surrounding area.
Areas we serve
Browse by state, then city.
California (3)
All of California · Costa Mesa · Jurupa Valley · Santa Maria