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, Penn Township administers the code itself: Section 63-32 of the Township Code says "The Township of Penn hereby elects to administer and enforce the provisions of this Article III," and the Township's Community Development page says "The Director of Community Development Department supervises and coordinates building code enforcement, zoning, sewage enforcement," with a Chief Building Inspector/Zoning Officer who "issues permits for new homes, additions, decks, and other residential and commercial structures." The Township office is at 2001 Municipal Court, Harrison City. Section 63-31 fills in the design data of Table R301.2(1), including "ICE SHIELD UNDERLAYMENT REQUIRED: Yes," and Chapter 63 changes nothing in the code's roofing provisions. Section 63-30 of the Township Code adopts the Uniform Construction Code "as amended and supplemented from time to time" and lists "The International Residential Code 2003 Chapter 43, Referenced Standards and Appendices A, B, C, D, G and L" among its parts, and the Township's pages name no code edition; this record has not read the 2003 edition's text and does not decide which edition the Township applies.
Permit process
The Penn Township code and pages read for this record do not say in terms whether a house reroof needs a permit. Article II of Chapter 63 of the Township Code, Building Permits, says in Section 63-5 "It shall be unlawful for any person, partnership, business or corporation to undertake or cause to be undertaken any construction or development anywhere within the Township of Penn unless an approved building permit has been obtained from the Zoning Officer," and in Section 63-9 "Building permits shall be required before any proposed construction or development is undertaken within any area of the Township of Penn, Westmoreland County, Pennsylvania." Section 63-6 defines CONSTRUCTION as "The construction, reconstruction, renovation, repair, extension, expansion, alteration or relocation of a building or structure, including the placement of mobile homes." The article names no roof work and has no exemption for minor or ordinary repairs. It is the Township's flood-damage article: its stated intent includes to "Encourage the utilization of appropriate construction practices to minimize flood damage in the future," and several of its application rules apply only in flood-prone areas. Section 63-19 says "Applications for a building permit shall be accompanied by a fee, payable to the Township of Penn, based upon the current township fee schedule," and no fee schedule is linked from the Township's Permits page. This record does not decide whether Article II reaches an ordinary house reroof outside flood-prone areas. The Township's Permits and Community Development pages (read October 7, 2026) say nothing on roofing either way; the department's notice of its online permit process says "If you have any questions, please contact the Community Development Department at 724-744-2171 ext. 210." 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." Before starting a reroof, ask the Community Development Department whether it requires a permit for the job. The department's notice says "Beginning Friday, March 13th, all permit applications will be handled online," through the Township's GovWell portal. Read for this answer: Chapter 63 of the Township Code, Building Construction (Article I, Construction Activities; Article II, Building Permits; Article III, Construction Codes, Uniform; Sections 63-1 to 63-37), in full; a search of the whole Township Code for "roof" and for "reroofing," which found no permit provision naming roof work; and the Township's Permits and Community Development pages and its online permit notice. The Township office is open Monday to Friday, 8:30 a.m. to 5:00 p.m., at 724-744-2171.