Pennsylvania enforces the 2021 IECC residential, with exceptions

Record of adoption

In force since

Jan 1, 2026

Legal citation

34 Pa. Code Sec. 403.21 as amended by Regulation #12-125 (55 Pa.B., Nov. 8, 2025); Construction Code Act, 35 P.S. 7210.304

Adopted by

Pennsylvania Department of Labor & Industry, adopting the UCC Review and Advisory Council’s recommendations (IRRC approved Oct 16, 2025)

Second reading

Agreed Oct 18, 2026

Applies

Statewide, with exceptions

State amendments

Major

Also called

UCC energy provisions, 34 Pa. Code Chapter 403

One 2021 IECC adoption covers residential and commercial energy. The filed rule lists many residential modifications (envelope tables, ducts, lighting, compliance paths).

Exceptions

• Philadelphia enforces its own Title 4 (Building Construction and Occupancy Code) with the Philadelphia Administrative Code as a local construction code; its 2021 I-Code update also took effect Jan 1, 2026, and applications before Jul 1, 2026, may use the 2018 editions
• Municipalities adopt ordinances to administer and enforce the UCC (Act 45 Sec. 501)

Coming next

• 2024 IECCPartial
  No date yetIn developmentPennsylvania Construction Code Act Sec. 108 (Council review); future amendment of 34 Pa. Code Sec. 403.21

  The Council’s page shows the 2024 code under review with comments open to Feb 2, 2027; no adoption or effective date was found.

How Pennsylvania adopts the IECC residential

• Agency rule
• The legislature sets the update schedule
• A recent law changed the process

Under the Construction Code Act (Act 45 of 1999, restructured by Acts 1 of 2011 and 36 of 2017), the Review and Advisory Council starts reviewing each new ICC triennial edition 21 months after publication, holds at least three public hearings, and adopts updated sections by majority vote when unopposed and by a two-thirds majority of its members for adopting or modifying other sections. L&I must then promulgate final-omitted regulations adopting the Council’s decisions without change within nine months of the Council’s report, with an effective date 33 months after review began; IRRC approved the 2021 package on Oct 16, 2025, it was published Nov 8, 2025, and took effect Jan 1, 2026. No bill or legislative vote is part of this process.

Cycle. Triennial by design (Council review starts 21 months after each ICC edition and rules take effect 33 months after review begins), but adoption has been irregular: 2015 I-Codes effective Oct 1, 2018, 2018 I-Codes effective Feb 14, 2022 (per L&I’s home page), 2021 I-Codes effective Jan 1, 2026.

Laws, rulings, and other actions

1. Nov 8, 2025Other action
   Regulation #12-125: UCC triennial update adopting the 2021 I-Codes (final-omitted)

   Adopts nearly all provisions of the 2021 ICC codes with Pennsylvania modifications, effective Jan 1, 2026, after IRRC approval on Oct 16, 2025.

2. Oct 20, 2025Other action
   Philadelphia L&I Code Bulletin B-2501: implementation of the 2021 International Codes

   Philadelphia moves its Title 4 construction code to the 2021 I-Codes from Jan 1, 2026, requires them for applications received on or after Jul 1, 2026, and keeps its Administrative Code as a local construction code.

3. Oct 25, 2017Legislation
   Act 36 of 2017 (P.L. 356, No. 36)

   Added Section 108 with the current Council schedule and two-thirds vote rule, amended Sections 107 and 304, required a re-review of the 2015 I-Codes, and let first-class cities adopt provisions of the 2018 ICC codes.

   Enacted Oct 25, 2017

   legis.state.pa.us (opens in a new tab)
4. Apr 25, 2011Legislation
   Act 1 of 2011HB 377, 2011 regular session

   Set a two-thirds Council vote for revisions sent to the Secretary, required public hearings and L&I adoption of the revisions without change, and added Section 901 subsections on log walls, one- and two-family sprinklers, floor fire protection and wall bracing.

   Enacted Apr 25, 2011, effective on enactment except the Section 107(c)(2) change effective Jul 1, 2012

   legis.state.pa.us (opens in a new tab)
5. Nov 10, 1999Legislation
   Act 45 of 1999 (P.L. 491, No. 45), Pennsylvania Construction Code Act

   Created the statewide Uniform Construction Code, adopted by L&I regulation, and the Review and Advisory Council; its Sections 107, 108 and 304 now set the update process.

   Enacted Nov 10, 1999

   legis.state.pa.us (opens in a new tab)

How it was checked

Verified

Two separate readings of the state’s own record agree, and the passage is on file word for word.

Read twice: a second, blind reading of the state’s record agreed with the first on Oct 18, 2026.

The state’s record was last read on Oct 18, 2026, from five source pages.

Evidence 6 sources

Sources for the record itself come first, the state’s own records ahead of others. A label marks a source about something else, such as an exception. A source marked secondary is not the state’s own record.

• “The effective date is January 1, 2026.”

• “The effective date is January 1, 2026.”

• “Updates the Uniform Construction Code by adopting nearly all the provisions of the 2021 International Code Council codes.”

• “The expected effective date of the final-form regulation: January 1, 2026”

• About a related rule or action

  “The Philadelphia Administrative Code shall continue as a local construction code”

Related pages

• See Pennsylvania’s IECC residential on the map
• IECC residential adoption in every state
• All six codes in Pennsylvania

Other codes in Pennsylvania

• NEC2020 NECPartial
• IBC2021 IBCVerified
• IRC2021 IRCVerified
• IFC2021 IFCVerified
• IECC commercial2021 IECCVerified