Tempe, AZ Accessory Structures: Tiny Homes (2026)

Tempe defines an accessory dwelling unit (ADU) as a subordinate dwelling that can be rented or leased separately from the main house, and Zoning and Development Code Section 3-402 sets the standards. 4 that tiny home construction is permissible for an ADU when built on a permanent foundation and compliant with the city's adopted building code for tiny homes. That building-code cross-reference points to Tempe City Code Section 8-300, which adopts Appendix BB of the 2024 International Residential Code and defines a TINY HOUSE as a dwelling of not less than 120 square feet and not more than 400 square feet of floor area, excluding lofts, that is not regulated by the Arizona Department of Housing's Manufactured Housing Division and is not a recreational vehicle.

Because a tiny-home ADU still has to satisfy the general ADU standards in Section 3-402, it also has to meet the same setbacks (5 feet minimum on rear, side and street side yards), height limits tied to the underlying zoning district, and lot-coverage counting as any other ADU, and it needs its own address, sewer and water connections, and full sleeping, sanitation and kitchen facilities. A tiny home ADU can be built on a lot with a single-family dwelling in any residential district identified in Section 2-102, counts toward the one-attached, one-detached ADU allowance per lot under an acre, and cannot be subdivided or sold separately from the main lot.

Building permits go through the Community Development Department's Building Safety Division, which verifies the permanent foundation and Appendix BB compliance before signing off on construction.