Maricopa, AZ Accessory Structures: ADU Rules (2026)
ADU rules in Maricopa, AZ, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Where allowed
- RS districts only, by right
- Barred districts
- RM, RH, RMHP
- Height over garage
- 25 ft max, pitched roof
- Setback rule
- Same as main building
- Rental rule
- Cannot be leased separately
Summary
Maricopa's zoning code permits a guest quarters (ADU) by right only on single-unit lots in RS districts, bars separate rental of the unit, and treats one built over a detached garage as a full main building for setback purposes.
Where guest quarters are located over a detached garage, the entire structure shall be considered a main building, subject to the zoning district standards for main buildings. No portion of this building shall be closer to any lot line than is permitted for any other main building, except on an alley where the detached garage may be within the setback.
B. Relation to Existing Structures. A detached accessory building may only be constructed on a lot on which there is a permitted main building to which the accessory building is related. An accessory building on an adjacent lot under the same ownership is not allowed; the two lots must be merged. However, an accessory building may be constructed prior to a permitted main building and used for not more than one year in connection with the construction of the main building; provided, that a permit is obtained for the entire project, including the accessory building, prior to the start of any construction.
C. Location. Accessory structures shall be located behind the front line of the primary structure, unless otherwise specified in this code.
1. Corner Lot. On a corner lot, no detached accessory building shall be located so as to project beyond the required front yard or the existing front line of the primary structure on any street frontage for lots less than one acre.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 26-10, passed April 21, 2026).
Full Breakdown
City code classifies a guest quarters as a second dwelling unit accessory to a single-family home, permitted by right only in RS residential districts. Table 18.35.020 lists it as not permitted in RM, RH, or RMHP districts. It cannot be leased, rented, or sublet separately from the primary residence on the same lot. Under MCC 18.80.020(A)(3), a guest quarters located over a detached garage is treated as a main building rather than an accessory structure, so it must meet the same setbacks as the primary house instead of the reduced accessory setbacks, except where the garage faces an alley. Height for guest quarters over a garage tops out at 25 feet with a pitched roof, versus 15 feet for an ordinary detached accessory building.
Violations & Fines
Renting a guest quarters as a separate unit, building one in an RM, RH, or RMHP district, or exceeding the height/setback standards without zoning administrator approval violates MCC 18.80.020 and can trigger permit denial or a stop-work order.
Frequently Asked Questions
Can I rent out a guest quarters separately from my house in Maricopa?
How tall can a guest quarters above a detached garage be?
Are ADUs allowed in Maricopa's multi-family zoning districts?
Sources & Official References
Other rules in Maricopa
How Maricopa compares: Easiest Cities to Build an ADU·Compare Maricopa to another location·View the Arizona accessory structures overview
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