300.25 Stair towers
What changed in 300.25
New section: where an exit stair enclosure needs a fire-rated separation from the rest of the building, only wiring for equipment the AHJ allows in that enclosure can go inside.
Point by point
- New section covering wiring inside exit enclosures, such as stair towers.
The full lesson is in the Pro Version
Get the whole breakdown
- 4 more points on exactly what changed
- The 2017 rule next to the 2020 rule, side by side
- Why it changed
- What to do and check on the job
One membership unlocks every NEC® change lesson for 2020, 2023 and 2026, plus every video, quiz, flashcard and the Testing Center.
Checking your membership…
This section across NEC® editions
2020 NEC®NewYou're here
New section: where an exit stair enclosure needs a fire-rated separation from the rest of the building, only wiring for equipment the AHJ allows in that enclosure can go inside.
2023 NEC®Revised
Exit stair rules now key on a fire-resistance rating, and a new exception lets egress lights at the stair's outside exterior door be fed from the stair's wiring.
Open the 2023 page →2026 NEC®No change
This section did not change from 2023 to 2026.
More 2020 changes in Article 300
This is a plain-English summary, not the NEC®'s exact wording. Always check the full section in the NEC® edition your area has adopted, plus any local amendments.
NEC® and National Electrical Code® are registered trademarks of the National Fire Protection Association (NFPA). Electrical Exam Coach is not affiliated with or endorsed by NFPA.
Find it faster on test day