Cost to build accessory dwelling unit

Looking for cost to build accessory dwelling unit in Gilbert, AZ? Call AccessoryDwellingUnit Pros for a contact a provider — no obligation. Licensed adu builders serve Gilbert 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 is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.

About this service

Determining the cost requires looking at site preparation, foundation work, and the level of interior finishing you choose. Costs change based on whether you opt for a pre-designed layout or custom architecture. You should research these costs when you are ready to evaluate the financial return of your property upgrade. Exact pricing confirmed free on the call.

Frequently asked in Gilbert

What are the disadvantages of ADUs?

Some disadvantages can include increased utility costs and potential impacts on existing property value if not well-integrated. You'll also need to consider the permitting process, which can take time. Discussing these with the pros who come out can give you a clearer picture for your Gilbert home.

How much does an ADU cost in Arizona?

The cost to build an ADU in Arizona varies widely based on size, materials, and site preparation. Expect a range influenced by factors like foundation type and whether you choose a prefab or custom build. We can give you a precise estimate for your Gilbert property.

What are the rules for ADUs in Arizona?

Arizona has statewide ADU laws, but local ordinances in cities like Gilbert can add specific requirements. These often cover setbacks, height, and parking. The specialists you speak with will be knowledgeable about Gilbert's specific regulations.

Is ADU allowed in Arizona?

Yes, ADUs are generally allowed across Arizona, with specific regulations varying by city and county. Gilbert has specific guidelines homeowners need to follow to ensure compliance. We can help you understand these rules for your specific location.

What are the rules for ADU in California?

California has specific ADU laws aimed at encouraging their development, often streamlining the permitting process. These rules focus on size limits, setbacks, and owner occupancy requirements. While this doesn't directly apply to Gilbert, understanding California's approach shows the trend.

Also serving nearby: Chandler · Mesa · Tempe · Phoenix · Scottsdale

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

Service area details

275,411residents

4,011per sq mile

7ZIP codes served

Serving all of Gilbert — population 275,411; about 4,011 residents per square mile across 68.7 sq mi. ZIP codes covered include 85233, 85234, 85295, 85296, 85297, 85298, 85299.

Neighborhoods served in Gilbert: Power Ranch, Agritopia, Windham Estates, Gilbert Commons, Warner Groves — and every surrounding area.