U.S. code adoption
Delaware — energy & appliance code adoption
Yes — effectively. This page summarizes electrical (NEC), appliance-listing (UL 858), fire-code, and energy-storage (UL 9540 / NFPA 855) code adoption for Delaware, with primary sources.
Is UL 858 required in Delaware?
Yes — effectively. Delaware 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.
Are NRTL-listed (UL / ETL / CSA) appliances required in Delaware?
Yes. Delaware's adopted code requires fixed electrical appliances to be listed by an NRTL (UL, ETL/Intertek, CSA, etc.) — NEC 110.3.
Which edition of the NEC does Delaware use?
Delaware has adopted the 2020 edition of the National Electrical Code (NEC). 2020 NEC currently in effect statewide; State Electrical Board has scheduled NEC 2023 to take effect January 1, 2026.
Is UL 9540 required for residential energy storage in Delaware?
Yes — effectively. Delaware requires NRTL listing for stationary energy storage systems (ESS) in dwellings, and UL 9540 is the controlling standard. ESS in residential dwellings governed by NFPA 1 Ch. 52, referencing UL 9540 listing and NFPA 855 installation standard. UL 9540A required to exceed the default 20 kWh / dwelling cap or reduce default 3-ft separation.
Is UL 9540A fire-propagation testing required in Delaware?
Yes — effectively. Delaware requires NRTL listing for energy storage systems, and UL 9540A is the controlling standard.
What is the residential energy-storage capacity limit in Delaware?
Delaware limits residential energy storage to 20 kWh per dwelling unit.
Which fire code does Delaware enforce?
Delaware enforces NFPA-1 2021. Delaware State Fire Prevention Commission adopts NFPA 1 (2021) and NFPA 101 (2021).
Code adoption summary
| NEC edition | 2020 NEC |
|---|---|
| Appliance listing (UL 858) | Effectively required |
| NRTL listing requirement | Required |
| Fire code | NFPA-1 2021 |
| IRC edition | 2015 IRC |
| UL 9540 (residential ESS) | Effectively required |
| UL 9540A propagation test | Effectively required |
| Residential ESS cap | 20 kWh / dwelling |
| NFPA 855 edition | 2020 |
Sources
- NFPA — NEC enforcement maps
- Delaware State Fire Prevention Regulations — 700
- Canary Media — Balcony solar in state legislatures