Accessory dwelling unit cost — Tempe, AZ

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

Pricing for an ADU is driven by the quality of finishes, the foundation type, and the complexity of your site’s terrain. Projects on flat, accessible lots are generally more affordable than those requiring significant grading or utility trenching. Exact pricing confirmed free on the call.

Frequently asked in Tempe

Also serving nearby: Chandler · Gilbert · Mesa · Phoenix · Glendale

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

Service area details

Serving all of Tempe — population 189,834; about 4,748 residents per square mile across 40.0 sq mi. ZIP codes covered include 85280, 85281, 85282, 85283, 85284, 85285, 85287, 85288.

Neighborhoods served in Tempe: Maple-Ash, Daley Park, University Heights, Kyrene, Corona del Sol — and every surrounding area.