STATE CAPITOL, PHOENIX –  House Bill 2928, a major reform to protect property rights and expand housing options for Arizona families, has been signed into law.

The new law, sponsored by House Majority Leader Michael Carbone, eliminates unnecessary local restrictions on accessory dwelling units (ADUs)—also known as casitas or guest houses—and requires counties to adopt consistent, fair rules allowing both attached and detached ADUs on lots zoned for single-family homes.

“Arizona homeowners should be able to use their property without being buried in red tape,” said Majority Leader Carbone. “Whether it’s a unit for an aging parent, a young adult, or a source of income, ADUs are a practical solution—and it’s time the law recognized that. We spent months working with counties and stakeholders to get this right, and we delivered.”

HB2928 sets statewide standards that prevent counties from blocking ADUs with burdensome parking requirements, design mandates, preexisting relationship rules, or costly construction conditions. It also prohibits excessive fees, unreasonable setbacks, or requirements for unnecessary public improvements that drive up housing costs.

The law includes exemptions for tribal lands, military areas, high-noise zones, and utility easements. It also allows counties to require septic system evaluations for ADUs not connected to sewer systems. Counties must adopt the required regulations by January 1, 2026—or the bill’s default provisions will automatically take effect.

This reform advances the priorities of the House Republican Majority Plan, which is focused on preserving the American Dream by defending individual rights, reducing government overreach, and keeping housing attainable for Arizona families.

“House Republicans are delivering results,” Majority Leader Carbone added. “This law gives homeowners more freedom, cuts through bureaucracy, and ensures Arizona families can thrive. It’s exactly the kind of policy leadership voters sent us here to provide.”

Michael Carbone is a Republican member of the Arizona House of Representatives serving Legislative District 25 which includes portions of Yuma, Maricopa, and La Paz Counties. He also serves as House Majority Leader. Follow him on X at @MichaelCarbone.