Pennsylvania mechanical, plumbing, fuel gas & energy codes
Pennsylvania's Uniform Construction Code (UCC) adopts the ICC codes statewide by regulation (34 Pa. Code Ch. 401/403) after review by the UCC Review and Advisory Council (RAC). The Department of Labor & Industry (L&I) runs it, and most municipalities enforce it locally.
Adopted codes
- Adopted as
- 34 Pa. Code §403.21 (Uniform Construction Code)
- Effective
- 2026-01-01
- Source
- Pennsylvania Bulletin, 55 Pa.B. 7701 (Nov 8, 2025)
- Last checked
- 2026-10-29 verified
- Notes
- Adopted without modification per the RAC's 2021 code report. Pennsylvania went straight from the 2018 to the 2021 I-Codes on Jan 1, 2026.
- Adopted as
- 34 Pa. Code §403.21 (Uniform Construction Code)
- Effective
- 2026-01-01
- Source
- Pennsylvania Bulletin, 55 Pa.B. 7701 (Nov 8, 2025)
- Last checked
- 2026-10-29 verified
- Notes
- Adopted without modification per the RAC's 2021 code report. Pennsylvania went straight from the 2018 to the 2021 I-Codes on Jan 1, 2026.
- Adopted as
- 34 Pa. Code §403.21 (Uniform Construction Code)
- Effective
- 2026-01-01
- Source
- Pennsylvania Bulletin, 55 Pa.B. 7701 (Nov 8, 2025)
- Last checked
- 2026-10-29 verified
- Notes
- Adopted without modification per the RAC's 2021 code report. Pennsylvania went straight from the 2018 to the 2021 I-Codes on Jan 1, 2026.
- Adopted as
- State energy code (per U.S. DOE BECP)
- Effective
- Res 2026-01-01; Com 2026-01-01
- Source
- U.S. DOE Building Energy Codes Program – Pennsylvania
- Last checked
- 2026-10-29 verified
- Notes
- With state amendments.
A2L refrigerants in Pennsylvania
Pennsylvania is on the 2021 IMC, which predates the 2024 A2L provisions. Act 123 of 2022 (Construction Code Act §901(j)) says a refrigerant approved under Clean Air Act §612 may be used even where the UCC prohibits it, as long as the equipment is listed and installed under EPA's use conditions. The exemption expires when L&I adopts the RAC's review of the 2024 ICC codes.
Source: https://www.legis.state.pa.us/WU01/LI/LI/US/HTM/2022/0/0123..HTM?82= · Last checked 2026-10-29 verified
Local amendments & things to watch
- Over 90% of Pennsylvania's 2,562 municipalities enforce the UCC themselves. In opt-out municipalities, L&I enforces commercial work and third-party agencies handle residential. verified source
- The RAC's 2021 report lists the IMC, IPC and IFGC as adopted without modification. The 2021 IECC and IRC were adopted with Pennsylvania changes. verified source