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The Code Question of the Day (CQD) is NECA and ELECTRICAL CONTRACTOR Magazine’s flagship National Electrical Code (NEC®) public forum for the industry. The daily distribution of Q&A generates a lively dialogue and shares relative Code-based practical responses.
October 2, 2026
Hi CQD, does swapping out a worn receptacle trigger the current GFCI and AFCI requirements, or do those only apply to new circuits? The duplex in question has no GFCI or AFCI protection anywhere and about a dozen receptacles need replacing. Thanks, Vern C.
October 1, 2026
Does 2020 NEC Section 300.22(C) Other Spaces Used for Environmental Air (Plenums) apply to one- and two-family dwellings, or are these occupancies exempt from the requirements of this section? Thank you in advance for your assistance. We look forward to your clarification, Hector V.
Good Morning, and thank you for the question. One- and two-family dwellings are not exempt from 300.22(C). The section applies to a space that was not built for air handling but is being used as a plenum but is not limited to a specific occupancy type.
What it does exclude is habitable rooms and areas whose primary purpose is not air handling, and the joist or stud spaces of a dwelling unit where the wiring passes through perpendicular to the long dimension of the space. Wiring run through those joist or stud spaces is outside the section. Any other space in the house that is carrying return air, such as the cavity above a suspended ceiling, is a plenum, and the wiring in it has to be one of the methods in 300.22(C)(1).
The rule has not changed from the 2020 edition through 2023 and 2026; the only difference is that it is now numbered 300.25(C) in the 2026 NEC.