Modular accessory dwelling unit — 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

A modular unit is built in a factory and then transported to your property to be finished on a foundation. You should consider this if you want a faster construction timeline with less disruption to your daily life. It is an efficient way to add high-quality space to your lot.

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, Naples, Downtown Long Beach, Alamitos Beach, Bixby Knolls — and every surrounding area.