Seven codes in two families

The electrical code, the five I-Codes, and NFPA 855, each on its own map: every state’s edition, the seal for each value, the changes ahead, and the states that leave adoption to cities and counties. Data as of Oct 20, 2026.

NFPA

NEC

National Electrical Code. The 2023 NEC leads with 20 states. Verified in 35 of 49, with a change ahead in seven.

2026 NEC 8
2023 NEC 20
2020 NEC 11
2017 NEC 2
2014 or older 3
Local adoption 5

NFPA 855

NFPA 855, Standard for the Installation of Stationary Energy Storage Systems. The 2020 NFPA 855 leads with 18 states. Verified in 22 of 49, with a change ahead in one.

2023 NFPA 855 14
2020 NFPA 855 18
Local adoption 1
Fire code predates NFPA 855 15
No data yet 1

I-Codes

IBC

International Building Code. The 2021 IBC leads with 19 states. Verified in 34 of 49, with a change ahead in eight.

2024 IBC 15
2021 IBC 19
2018 IBC 5
2015 IBC 3
2012 or older 2
Local adoption 5

IRC

International Residential Code. The 2021 IRC leads with 14 states. Verified in 31 of 49, with a change ahead in nine.

2024 IRC 13
2021 IRC 14
2018 IRC 8
2015 IRC 5
2012 or older 1
Local adoption 6
State’s own or another code 2

IFC

International Fire Code. The 2024 IFC leads with 12 states. Verified in 32 of 49, with a change ahead in six.

2024 IFC 12
2021 IFC 12
2018 IFC 3
2015 IFC 3
2012 or older 2
Local adoption 1
State’s own or another code 16

IECC residential

International Energy Conservation Code, residential. The 2021 IECC leads with 10 states. Verified in 27 of 49, with a change ahead in eight.

2024 IECC 9
2021 IECC 10
2018 IECC 7
2015 IECC 8
2012 or older 6
Local adoption 5
State’s own or another code 2
No data yet 2

IECC commercial

International Energy Conservation Code, commercial. The 2021 IECC leads with 14 states. Verified in 26 of 49, with a change ahead in six.

2024 IECC 9
2021 IECC 14
2018 IECC 5
2015 IECC 3
2012 or older 5
Local adoption 4
State’s own or another code 9

Each bar shows how many states enforce each edition. The darkest step is the newest edition. Local adoption and a state’s own code are the hatched and dotted steps.

Topic views

One rule across the map, starting with rapid shutdown for photovoltaic systems in NEC 690.12.

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