Accessory dwelling unit construction cost

Looking for accessory dwelling unit construction cost in San Bernardino, CA? Call AccessoryDwellingUnit Solutions for a contact a provider — no obligation. Licensed adu builders serve San Bernardino and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.

About this service

The cost of building an ADU depends on your choice of materials, the square footage, and whether you are doing a garage conversion or a new detached build. Site access and utility upgrades also play a big role in the final bill. Exact pricing confirmed free on the call.

Frequently asked in San Bernardino

What are the disadvantages of ADUs in San Bernardino?

How much does an ADU cost in California?

What are the rules for ADUs in California?

California has state laws promoting ADUs, but San Bernardino County may have specific local requirements for permitting, zoning, and design. These can cover aspects like setbacks, height limits, and parking. Ensuring compliance is key to a successful project. Call for advice tailored to your location.

Is an ADU allowed in Maryland?

This information pertains to San Bernardino, California. Maryland has its own set of regulations for accessory dwelling units. If your interest lies in Maryland, you'll need to consult local resources there for specific ADU guidelines. For California projects, we can assist.

California has had grant programs aimed at supporting ADU development, though their availability and specifics can change. It's important to research current funding opportunities through state and local agencies. Professionals can often help identify potential financial assistance. We can help you connect with them.

How do I get started with an ADU in San Bernardino?

Also serving nearby: Rialto · Fontana · Jurupa Valley · Rancho Cucamonga · Riverside

All cities in California →

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

Service area details

223,728residents

3,602per sq mile

8ZIP codes served

Serving all of San Bernardino — population 223,728; about 3,602 residents per square mile across 62.1 sq mi. ZIP codes covered include 92401, 92402, 92403, 92404, 92405, 92406, 92407, 92408.

Neighborhoods served in San Bernardino: Downtown San Bernardino, Muscoy, Loma Linda (adjacent), Highland (adjacent), Grand Terrace (adjacent) — and every surrounding area.