ZoningVerdict

Accessory dwelling units in Maricopa, AZ

What the Maricopa zoning ordinance says about accessory dwelling units, district by district. Section numbers link to the official ordinance.

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Maricopa's zoning code does not have a standalone "accessory dwelling unit" or ADU-by-right provision. It regulates detached living space as a "guest quarter": where guest quarters are located over a detached garage, the entire structure is treated as a main building subject to the district's main-building setback standards (MCC 18.80.020). A detached accessory structure that has not been approved as a guest quarter may add bathroom facilities only with zoning administrator and building official approval, and the applicant must sign a recorded restrictive covenant prohibiting use of the structure as a second dwelling unit (MCC 18.80.020). A detached accessory structure may not have separate housekeeping plumbing (a kitchen or laundry) unless approved as a guest quarter; MCC 18.120.010 (Accessory uses) is the section cross-referenced for this, but an independent re-check this session found no distinct "guest quarters" subsection with its own size/location standards inside 18.120.010 itself, so the precise guest-quarter standard likely lives in a different, not-yet-located section. Guest quarters are permitted by right (P) only in the RS-1 district in the sampled portion of the residential use table (Table 18.35.020), and not permitted (X) in RS-3, RS-4, and RS-5 in that same sample; review-gated: confirm the complete Table 18.35.020 guest-quarters row directly before relying on a specific district. Separately, Arizona's 2024 accessory dwelling unit statute (A.R.S. Sec. 9-461.18, enacted by HB2720) requires cities and towns with 75,000 or more residents to allow ADUs by right on single-family lots. The City of Maricopa's own population page states approximately 73,300 residents, but that figure is a stale marketing-page snapshot. Independent verification against the U.S. Census Bureau QuickFacts page (Vintage 2025 estimate) and the Arizona Office of Economic Opportunity / Maricopa Association of Governments official municipal estimates (July 1, 2024: approximately 73,800; July 1, 2025: approximately 78,200) shows Maricopa has already grown past the 75,000-resident threshold. This pack now hedges toward A.R.S. Sec. 9-461.18's by-right ADU mandate likely applying to Maricopa, not the reverse; this pack found no local ordinance adopting HB2720-style ADU standards voluntarily, so if the statute applies, Maricopa's actual practice for permitting ADUs by right on single-family lots may not yet be reflected in Title 18's guest-quarter framework. Confirm current population figures, state compliance status, and any ordinance changes directly with Development Services (520-568-9098) before relying on this conclusion.

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