Local authority · Arizona
Mesa — energy & appliance code adoption
Yes — effectively. Arizona has no statewide building or electrical code. Mesa's locally adopted ordinance is the operative authority. Below: how Mesa differs from Arizona on appliance listing, NEC, fire code, and energy storage, with sources.
Is UL 858 required in Mesa?
Yes — effectively. Mesa requires fixed household appliances to be listed by a Nationally Recognized Testing Laboratory (NRTL), and UL 858 is the de-facto listing standard a household electric range must meet. UL858 is the standard NRTLs use for household electric cooking appliances.
Are NRTL-listed (UL / ETL / CSA) appliances required in Mesa?
Yes. Mesa's adopted code requires fixed electrical appliances to be listed by an NRTL (UL, ETL/Intertek, CSA, etc.) — Mesa Building Code / NEC 110.3(B). NRTL listing required; installed per the listing.
Which edition of the NEC does Mesa use?
Mesa has adopted the 2023 edition of the National Electrical Code (NEC), effective 2026-01-08. Mesa adopted the 2023 NEC together with the 2024 ICC family; effective Jan 8, 2026. Prior edition was 2017 NEC.
Is UL 9540 required for residential energy storage in Mesa?
Yes. Mesa's adopted code requires UL 9540 listing for stationary energy storage systems (ESS) in dwellings. 2024 IFC §1207 codifies UL 9540 listing and NFPA 855 (2023). 9540A required to exceed 20 kWh dwelling cap or tighten spacing. Mesa FD plan review for ESS >20 kWh.
Is UL 9540A fire-propagation testing required in Mesa?
Yes — effectively. Mesa requires NRTL listing for energy storage systems, and UL 9540A is the controlling standard.
What is the residential energy-storage capacity limit in Mesa?
Mesa limits residential energy storage to 20 kWh per dwelling unit.
Which fire code does Mesa enforce?
Mesa enforces IFC 2024. Enforced by Mesa Fire & Medical Department.
Code adoption summary
| NEC edition | 2023 NEC |
|---|---|
| Appliance listing (UL 858) | Effectively required |
| NRTL listing requirement | Required |
| Fire code | IFC 2024 |
| IRC edition | 2024 IRC |
| UL 9540 (residential ESS) | Required |
| UL 9540A propagation test | Effectively required |
| Residential ESS cap | 20 kWh / dwelling |
| NFPA 855 edition | 2023 |
Sources
- City of Mesa Development Services — Mesa Building Code
- City of Mesa — Development Codes & Regulations