Gilbert to revise ‘habitable’ definition to align ADU calculations with state law

Town staff recommended a targeted change to Gilbert’s Land Development Code to update the definition of “habitable” so accessory dwelling unit (ADU) square‑foot calculations conform to state law and earlier town ADU amendments.

Background: staff explained that House Bill 2720 (2024) required municipalities to adopt ADU regulations by Jan. 1, 2025, and Gilbert amended its code in December 2024 to comply. The state law’s definition of gross floor area refers to the interior area of a dwelling unit, and the town’s existing “habitable” definition excluded bathrooms, toilet rooms, closets, halls and storage. That exclusion affected how the town calculated ADU size limits.

Proposed change: staff said the new definition would describe habitable space as “space in a building used for the purposes including living, working, sleeping, sanitation, eating, cooking, and condition storage, recreation, or any combination of the above,” explicitly including the previously excluded spaces so they count toward gross floor area for ADU size limits. A staff presenter said the ADU regulation adopted in December does not require cooking facilities; if a unit has cooking facilities, the square footage will be counted.

Process and next steps: the Planning Commission reviewed the text amendment last month and recommended approval. Staff told council the amendment will appear on an upcoming council meeting agenda for action. Council members asked clarifying questions about whether cooking facilities were required; staff answered that cooking facilities are not required by the ADU text amendment.

Ending: The council did not take action at the study session; staff will bring the code amendment forward for a public hearing and council decision.