Accessory dwelling unit cost — San Diego, CA

Last updated: September 24, 2026

What affects the price

Building an ADU is a major project, and the final bill depends on a few key things. Site prep is a big factor; if your land is sloped or needs extensive utility connections, costs go up. The materials you choose—from siding to kitchen finishes—also change the math significantly. Whether you’re building a detached unit or converting an existing garage shifts the permit requirements and structural work needed. We provide exact pricing confirmed free on the call.

About this service

The investment required for an ADU depends on your site conditions, the complexity of the design, and the materials selected for the interior. Larger units with custom features naturally shift the price higher compared to standard, compact models. Exact pricing confirmed free on the call.

Frequently asked in San Diego

Also serving nearby: El Cajon · Chula Vista · San Marcos · Escondido · Carlsbad

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

Service area details

Serving all of San Diego — population 1,388,320; about 4,257 residents per square mile across 326.1 sq mi. ZIP codes covered include 92101, 92102, 92103, 92104, 92105, 92106, 92107, 92108.

Neighborhoods served in San Diego: La Jolla, North Park, Mira Mesa, Point Loma, Coronado — and every surrounding area.