Adopted building code
The 2021 International Residential Code, as adopted by the State in the Pennsylvania Uniform Construction Code (UCC). 34 Pa. Code 403.21(a)(7) adopts "The 'International Residential Code of 2021,' except that:" followed by the State's list of exclusions and modifications, effective January 1, 2026 (55 Pa.B. 7701). None of the State's changes touches Chapter 9, Roof Assemblies, or Section R803, Roof Sheathing, so those apply as the International Code Council publishes them. Work on existing buildings is also pointed to the State's existing-building code: "The repair, alteration, change of occupancy, addition and relocation of existing buildings must comply with Chapter 34 of the 'International Building Code of 2021' or with the 'International Existing Building Code of 2021'" (34 Pa. Code 403.21(f)). The UCC is the minimum everywhere in the state: "no municipality may propose or enact any ordinance which is less than the minimum requirement of the Uniform Construction Code" (Pennsylvania Construction Code Act, Act 45 of 1999, section 503(b)). The Act also lists work it "shall not apply to", including "Alterations to residential buildings which do not make structural changes or changes to means of egress" or to "Repairs to residential buildings," in each case "except as might be required by ordinances" kept in force under section 303(b)(1) or adopted under section 503 (Act 45 section 104(b)(5) and (6); 34 Pa. Code 403.1(b)(8) and (9)). The Act defines a repair as "The reconstruction or renewal of any part of an existing building for the purpose of its maintenance." So whether the code's roofing rules reach a given house reroof depends on the municipality's own ordinances. Everything above is Pennsylvania state law, the same in every municipality. Locally, Worcester Township administers the code: Section 52-1 of the Township Code says "Worcester Township hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act," the Township takes building permit applications through its online Construction Permit Application, and its 2026 fee schedule attaches, as Appendix a, the Pennsylvania Uniform Construction Code permit fee schedule of Barry Isett & Associates, Inc. Section 52-2 says "The Uniform Construction Code, contained in 34 Pa. Code, Chapters 401-405, as amended from time to time, is hereby adopted and incorporated herein by reference as the building code of Worcester Township." Chapter 52 changes nothing in the code's roofing provisions. Section 52-6 of the Township Code names "The 2003 Edition of the International Building Code (IBC)" and the Township's pages name no edition; this record has not read the 2003 edition's text and does not decide which edition the Township applies.
Permit process
No Worcester Township text read for this record names reroofing as permit work or as exempt. Chapter 52 of the Township Code (Ord. No. 199, June 16, 2004, as amended) adopts the Uniform Construction Code "as amended from time to time" and, in Section 52-6, keeps in force provisions adopted on or before July 1, 1999, revising "The 2003 Edition of the International Building Code (IBC)" so that its scope section reads "These regulations shall control all matters concerning the construction, alteration, addition, repair, removal, demolition, use, location, occupancy and maintenance of all buildings and structures"; Section 52-6A also says the Township "reserves the right to enforce, without limitation, all other building code provisions not specifically listed below which were adopted on or before July 1, 1999," and those provisions are not published in the Township Code. No section of the Township Code names roof work as permit work or as exempt. The Township's online Construction Permit Application (read October 9, 2026) lists building work types that include "Deck/Patio with Roof" and "Interior Alteration" and none for roofing, and says "If the work you are applying for is not listed in any of the subcodes, please contact us at (610) 584-1410 before submitting your application. Some work may not require a permit, and a quick conversation can help prevent unnecessary applications." The 2026 fee schedule has no roofing line. Under state law, Act 45 section 104(b)(5) and (6) list "Alterations to residential buildings which do not make structural changes or changes to means of egress" and "Repairs to residential buildings" among work the Act does not apply to, "except as might be required by ordinances in effect pursuant to section 303(b)(1) or adopted pursuant to section 503," and 34 Pa. Code 403.62(c) says "A permit is not required for the exceptions listed in § 403.1(b) (relating to scope) and the following, if the work does not violate a law or ordinance." This record does not decide whether the Township requires a permit for an ordinary reroof; ask the Township at 610-584-1410 before work starts, as its application asks. The Permits page says "Payment for building permits is due at time of permit pickup," and the 2026 fee schedule lists a "Penalty fee for failure to obtain a permit in addition to permit fee" of "2x permit fee." The Township office is open Monday to Friday, 8:00 am to 4:30 pm. Read for this answer: Chapter 52 of the Township Code, Construction Codes, Uniform (Sections 52-1 to 52-8), in full; Chapter 51, Building Permit Procedures, in full; every page of a search of the whole Township Code for "roof" and for "reroofing"; the Permits and Documents, Forms & Permits pages; the online form list and Construction Permit Application; and the 2026 fee schedule.