City · Arizona
ADU rules in Gilbert
These are the primary sources for accessory dwelling unit regulations in Gilbert: the city's own zoning code, planning department pages, and permit guides. Start here before talking to anyone: the rules below are what your permit reviewer will apply.
Rules at a glance
One detached ADU per lot as of right in all single-family districts (use table lists ADU under 1,000 sq ft as P in SF-43 through SF-A); a second detached ADU is allowed on parcels of one acre or more if at least one ADU is a restricted-affordable unit.
LDC ch. 1 § 5.2.3(3)(a), (c); Table 3.1.2ADU must be subordinate to the primary dwelling and cannot exceed 75% of its gross square footage; also capped by the base district's lot coverage and height limits. Under 1,000 sq ft: building permit only. Over 1,000 sq ft but under 75% GFA: Administrative Use Permit. Facility Manager ADUs in non-residential districts are capped at 2,000 sq ft livable area.
LDC ch. 1 § 5.2.3(4)(a)-(c), 5.2.3(A), 5.2.3(B)(1)(a)No owner-occupancy requirement appears anywhere in the LDC (searched full current text), and state law prohibits requiring any familial, marital, employment or other preexisting relationship between the owner or occupant of the main dwelling and the ADU occupant.
LDC ch. 1 § 5.2.3 (no such requirement); A.R.S. § 9-461.18(B)(2)Section 5.2.3 sets no parking standard and the LDC off-street parking table (Section 5.3) has no ADU row; state law bars municipalities from requiring additional parking (or fees in lieu) to accommodate an ADU.
LDC ch. 1 §§ 5.2.3, 5.3 (no ADU parking requirement); A.R.S. § 9-461.18(B)(3)ADUs up to 1,000 sq ft are a permitted use in all single-family districts (building permit only). ADUs over 1,000 sq ft but under 75% of the primary dwelling's gross floor area require an Administrative Use Permit (staff-level, no public hearing) plus a building permit.
LDC Table 3.1.2 (ADU Under 1000 SF: P; Over 1000 SF: A); § 5.2.3(B)(1)(a)LDC 5.2.3(4)(f) states 'Separate renting or leasing of ADUs from the principal dwelling is permitted' (mirrors A.R.S. 9-461.18(B)(1), which bars prohibiting separate long-term rental). Vacation/short-term rentals are regulated by Municipal Code ch. 14, art. III (license required, Sec. 14-78) under Arizona's state-preempted STR regime (A.R.S. 9-500.39); no ADU-specific STR ban found.
LDC ch. 1 §§ 5.2.3(4)(f), 5.1.2; Code of Gilbert Sec. 14-78The fine print: 7 caveats that can change the picture
- Size and permit path split at 1,000 sq ft: at or under 1,000 sq ft an ADU may sit outside the building envelope with 5-foot minimum rear/side setbacks (plus a 1-foot stepback per foot of height over 10 feet); over 1,000 sq ft it needs an Administrative Use Permit and must be inside the building envelope.
- ADU must be built after the primary dwelling, be subordinate to it, and cannot exceed the base zoning district's lot coverage or height limits.
- The third (additional detached) ADU on 1+ acre parcels is allowed only if at least one ADU is a restricted-affordable unit (deed-restricted or development agreement, rented to households at up to 80% of area median income per A.R.S. 9-461.18(I)(6)).
- Exterior design standards still apply (front elevation articulation, architectural treatment, screened ground-mounted mechanical), but the ADU is not required to match the primary dwelling's design.
- ADUs in non-residential districts are limited to Facility Manager Dwelling Units for listed uses (max 2,000 sq ft livable area).
- Gilbert publishes the Land Development Code as a single consolidated PDF on gilbertaz.gov, so no stable deep link to Section 5.2.3 exists; the PDF URL serves the latest consolidated version.
- HOA and CC&R restrictions may still apply on top of town rules (noted in the town's own ADU guide).
Summarized from Gilbert's ordinance text, read July 2026; every row links the code section it came from. Rules often vary by zone and lot, so treat this as orientation, not a permit determination, and confirm with the planning department before you commit to a design.
ADU regulations
- gilbertaz.govOfficial sourceVerified July 2026https://www.gilbertaz.gov/departments/development-services/planning/land-development-code
- gilbertaz.govOfficial sourceVerified July 2026https://www.gilbertaz.gov/home/showpublisheddocument/42419/638894726134070000
- gilbertaz.govOfficial sourceVerified July 2026https://www.gilbertaz.gov/home/showdocument?id=2344
Short-term rental rules
Planning to rent your ADU on Airbnb or VRBO? Gilbert regulates short-term rentals separately; check these before counting on nightly rental income.
Arizona statewide law also applies
Arizona sets baseline ADU rights at the state level. Where local rules are stricter than state law allows, state law usually wins, so both are worth reading.
See Arizona statewide rulesSpotted something outdated?
Zoning codes change. If a link is dead or Gilbert has updated its ordinance, report it and we'll verify against the official source.
Report a correctionReady to build?
Planning an ADU in Gilbert?
Tell us about your project and we'll match you with vetted local designers and builders as we bring them online. No cost, no obligation.