Arizona Unveils Sweeping ADU Reforms to Broaden Housing Choices

By Jonathan Eberle |

Arizona homeowners will soon benefit from enhanced regulations allowing the construction of accessory dwelling units (ADUs) on their properties. This change is a result of House Bill 2928, recently signed into law and designed to alleviate housing shortages and bolster property rights statewide.

Introduced by House Majority Leader Michael Carbone, the legislation outlines uniform rules to limit local governments’ authority in imposing restrictions on ADUs—commonly referred to as casitas or guest houses—located on single-family zoned lots.

“Arizona homeowners should be able to use their property without excessive red tape,” Carbone stated. “ADUs serve a practical purpose, whether for family members or rental income, and it’s time the law reflected that reality.”

The new law mandates that counties establish standard guidelines by January 1, 2026. If they fail to do so, default provisions will automatically become effective. Furthermore, it prohibits local authorities from enforcing burdensome design standards, inflated parking requirements, or expensive infrastructure developments that have historically hampered ADU construction.

Significantly, the law disallows regulations that require a preexisting relationship between homeowners and ADU occupants. It also limits fees and setback stipulations that typically escalate construction costs and affirms the right to build both attached and detached ADUs on single-family residential lots.

While the legislation allows for exceptions regarding tribal lands, military zones, high-noise sectors, and utility easements, it still gives counties the discretion to mandate septic evaluations when necessary.

Supporters assert that this measure represents a substantial step in addressing Arizona’s ongoing housing affordability crisis. By allowing more versatile use of existing properties, advocates believe the bill will alleviate some pressure on the housing supply without requiring large-scale development.

“This law enhances homeowner autonomy, reduces bureaucratic barriers, and ensures that Arizona families can prosper,” Carbone noted.

This reform aligns with the broader objectives outlined in the House Republican Majority Plan, which emphasizes minimizing government intervention while promoting individual rights.

As Arizona’s population continues to grow swiftly, lawmakers from both parties are exploring innovative housing solutions. ADUs, which have been effectively utilized in other states to enhance density without disrupting neighborhood aesthetics, are increasingly regarded as a viable strategy to meet rising demands.

With the passage of HB 2928, attention now turns to its implementation as counties prepare to establish the necessary regulations by the deadline in 2026.