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, Hanover Township takes zoning and building permit applications at its Township office, 2731 State Route 18, Hookstown (724-899-2642), and its Zoning & Building page (read October 10, 2026) says "In 2006 the Township adopted the Universal Construction Code for all new construction" and "The Township uses the services of a third party inspector, Middle Department Inspection Agency, to do all residential and commercial inspections"; the page lists a Building Permit Inspector for that agency (1-800-922-6342) and a Zoning Officer (724-968-9263). The Township's ordinance adopting the Uniform Construction Code is not among the ordinances its Ordinances page lists, and its 2026 fee resolution refers to a "Hanover Township Code of Ordinances, Construction Code" that is not posted on the Township's site, so that ordinance was not read for this record. The Township's pages and posted forms name no code edition.
Permit process
Hanover Township's pages read for this record do not say whether a house reroof needs a permit. The Township's Zoning & Building page says "A building permit and inspections are required for all new construction, including renovations, remodeling, and additions. Certain project including agricultural buildings, renovations or remodeling may be exempt, but it is best to contact the Zoning Officer before beginning any construction project" and "Zoning Permits are required for most construction projects"; it names no roof work. The permit application the Township posts, an agency form, lists "New Building Addition Alteration Repair Demolition Relocation Energy" among its types of work and has no roofing box, and the agency guidelines for single family dwellings and residential additions name roof only as a framing item to be shown on plans for new work. The Township's 2026 fee resolution (Resolution No. 2026-3), read from the rendered page images of its scanned file, prices "alterations, renovations to 500 square feet" in its building inspection fee schedule and names roof only in its definition of square footage ("roofed patios"); it has no reroofing line. The Township's Zoning Ordinance (Ordinance No. 59), Section 402.1, requires a zoning permit before a person may occupy or use vacant land, occupy or use a structure "hereafter constructed, reconstructed, moved or enlarged," change a use or change a nonconforming use, and names no roof work. The Township's ordinance adopting the Uniform Construction Code is not among the ordinances its Ordinances page lists, and its 2026 fee resolution refers to a "Hanover Township Code of Ordinances, Construction Code" that is not posted on the Township's site, so that ordinance was not read for this record. 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 state whether the Township requires a permit for a house reroof; ask the Township office (724-899-2642) or its Zoning Officer before starting. The office is open Monday to Friday, 8:00 AM to 4:00 PM. Read for this answer: the Township's Zoning & Building, Ordinances, Forms & Links, Departments and Contact pages; the Zoning Ordinance (Ordinance No. 59), searched for permit provisions and for roof, repair and reroofing; the posted construction permit application and zoning application; the agency's guidelines for single family dwellings, residential additions and decks; and the 2026 fee resolution.