Accessory dwelling unit construction cost — Long Beach, 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

The cost to build an ADU depends on factors like your foundation type, utility connection distances, interior finish choices, and whether you are doing a detached build or a garage conversion. We provide an exact pricing confirmed free on the call.

Frequently asked in Long Beach

Also serving nearby: Carson · Compton · Westminster · Norwalk · Huntington Beach

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More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of Long Beach — population 449,468; about 8,870 residents per square mile across 50.7 sq mi. ZIP codes covered include 90801, 90802, 90803, 90804, 90805, 90806, 90807, 90808.

Neighborhoods served in Long Beach: Belmont Shore, Downtown Long Beach, Lakewood Village, Naples, Alamitos Beach, Bixby Knolls — and every surrounding area.