The Maricopa County Planning and Zoning Commission on Nov. 6 recommended that the Board of Supervisors adopt a modernized zoning ordinance that streamlines land‑use categories, adds definitions for contemporary uses and sets new standards for accessory dwelling units, short‑term rentals and battery energy storage systems (BESS).

Planning staff presented a consolidated draft that reduced the number of land-use categories, introduced clearer development‑standard tables, moved temporary-use permits to the commission’s process for faster review, and added definitions for data centers and BESS. Staff said the draft implements the state ADU statute and includes new short‑term‑rental rules (one STR per property; owner-occupancy required when an ADU exists).

The proposal for BESS drew the most public attention. Staff proposed a 100‑foot minimum setback from the property line and — initially — a 500‑foot minimum separation from existing off‑site residential dwellings, citing recommendations from the Arizona Fire and Medical Authority and local fire districts. Staff said the 500‑foot figure reflected past negotiations and fire‑safety recommendations but acknowledged industry and trade groups had pushed back.

Trade groups and large utilities urged the county to align with national or local NFPA/UL guidance. Autumn Johnson, executive director of the Arizona Solar Energy Industries Association, and Ben Graff, representing APS, urged measured standards and a waiver process so utility‑scale projects are not unintentionally precluded. Graff argued a hard 500‑foot rule could “reduce the number of parcels exponentially” available for BESS siting and hamper efforts to expand grid storage capacity.

Fire and emergency‑response officials offered a split perspective. Rural Metro Fire Marshal Diamond said modern systems and response coordination support shorter setbacks and he “agree[d] with the 100‑foot separation.” Robert Olmstead, fire marshal for the Arizona Fire and Medical Authority, who has overseen local BESS incidents, recommended a more cautious approach and said he is “comfortable with 500 feet,” citing concerns about smoke composition and potential evacuations in past incidents.

After public comment and internal discussion, commissioners directed staff to remove the proposed 500‑foot residential separation from the draft sent to the Board of Supervisors while retaining the 100‑foot property‑line setback and preserving case‑by‑case review via the IUPD overlay where greater separation could be required. Commissioners also agreed to recommend: (1) permitting ADU changes that comply with state statute; (2) allowing one STR per property with owner occupancy requirements for ADU properties; (3) extending plan‑of‑development (POD) validity to 3 years with administrative extensions; and (4) adding administrative waiver authority for large solar perimeter landscaping requirements.

Vice Chair Millhaven moved and Commissioner Rockwellick seconded the recommendation. The commission approved sending the ordinance update — with the commission’s modifications — to the Board of Supervisors by roll call vote, 8–0.

Next steps: the Board of Supervisors will consider the zoning-ordinance update at an upcoming hearing; BESS-specific setbacks remain subject to further Board discussion and local fire‑code authority.