Accessory dwelling unit construction cost

Looking for accessory dwelling unit construction cost in Phoenix, AZ? Call AccessoryDwellingUnit Services for a contact a provider — no obligation. Licensed adu builders serve Phoenix 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 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 Phoenix

What are the disadvantages of ADUs in Phoenix?

In Phoenix, potential disadvantages might include ensuring adequate cooling for the desert climate and navigating the permitting process, which can have its own set of requirements. Water usage and landscaping considerations are also important. Local ADU specialists are well-equipped to address these Phoenix-specific concerns.

How much does an ADU cost in Phoenix?

What are the rules for ADUs in Phoenix?

Can I get advice on building an ADU in Phoenix?

Absolutely. Seeking advice from experienced ADU construction professionals in Phoenix is a smart first step. They can assess your property's suitability, discuss design options, and guide you through the permitting and construction phases. This professional insight ensures a successful outcome for your ADU project.

What permits are needed for ADUs in Phoenix?

How do ADUs increase property value in Phoenix?

Adding an ADU in Phoenix can significantly enhance your property's value and its potential for rental income. The demand for additional living space is high in many Phoenix neighborhoods, especially with the city's growth. A well-designed ADU can make your home more attractive to a wider range of buyers or renters.

Also serving nearby: Glendale · Scottsdale · Tempe · Peoria · Surprise

All cities in Arizona →

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

Service area details

1,650,070residents

3,183per sq mile

8ZIP codes served

Serving all of Phoenix — population 1,650,070; about 3,183 residents per square mile across 518.3 sq mi. ZIP codes covered include 85001, 85002, 85003, 85004, 85005, 85006, 85007, 85008.

Neighborhoods served in Phoenix: Scottsdale, Tempe, Glendale, Arcadia, Paradise Valley — and every surrounding area.