AZ HB4028

Removes the 1,000 square foot cap on accessory dwelling units (ADUs), allowing them to be up to 75% of the main dwelling's gross floor area with no maximum size limit.

Eliminates the restriction limiting rear or side setbacks to no more than five feet from property lines for ADUs.

Prohibits municipalities from requiring administrative use permits for ADU construction, requiring ADUs to meet municipal building elevation criteria, or requiring ADUs to be located entirely within setback-defined building areas.

Extends the compliance deadline for municipalities to adopt ADU regulations from January 1, 2025 to January 1, 2027, after which ADUs would be allowed without limits if no regulations are adopted.

Applies to municipalities with populations over 75,000 and continues to exempt tribal lands, military airport vicinities, and areas near airports with noise levels above 65 decibels.