Accessory dwelling unit homes — 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
These are fully functional, independent homes located on the same lot as a primary residence. They include all essential facilities for sleeping, cooking, and sanitation. People choose these homes to create more living space for family members or to build a long-term investment property. Costs are driven by finishes, size, and site accessibility. Exact pricing confirmed free on the call.
Frequently asked in Costa Mesa
What is the cost to build an accessory dwelling unit in Costa Mesa?
What are the benefits of a backyard accessory dwelling unit in Costa Mesa?
Can I get a 24-hour ADU service in Costa Mesa?
Who are the best accessory dwelling unit companies in Costa Mesa?
The best ADU companies in Costa Mesa are those that are licensed, insured, and have a strong portfolio of successful ADU projects. They understand California building codes and local Costa Mesa regulations. These companies focus on quality craftsmanship and client satisfaction. We can help you find experienced companies ready to bring your ADU vision to life. They are dedicated to excellence.
What is involved in ADU building in Costa Mesa?
What are the different types of ADU housing available?
Are there accessory dwelling unit contractors serving San Diego from 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 Verde, South Coast Metro, Westside Costa Mesa, College Park, Eastside Costa Mesa — and every surrounding area.
Areas we serve
Browse by state, then city.
California (3)
All of California · Costa Mesa · Jurupa Valley · Santa Maria