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, Alsace Township takes building permit applications at its Township office, 65 Woodside Avenue, Temple, and its Building/Permitting page says "Technicon enterprises is our board appointed Building and code officer" and sends inspection scheduling and project questions to Technicon Enterprises Inc. at 610-286-1622. Chapter 84 of the Township Code adopts the Uniform Construction Code "as amended from time to time" and fills in the residential code's Table R301.2(1), including "Ground snow load: 30 psf" and "Ice shield underlayment required: Yes"; it changes nothing in the code's roofing provisions. The same page tells applicants to comply with "ALL applicable Sections of the 2018 International Building, Plumbing, Mechanical, Electrical, Energy, and Fire Codes" and names no edition of the International Residential Code; the text above is the 2021 edition's, and this record has not read the 2018 editions' text.
Permit process
Alsace Township's pages and Code read for this record do not say whether a house reroof needs a permit. Chapter 84 of the Township Code (Ord. No. 2004-2 and Ord. No. 2004-3), read in full, adopts the Uniform Construction Code "as amended from time to time" as the municipal Building Code and says "this section shall apply to all construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, maintenance, removal and demolition of every building and/or structure occurring in Alsace Township on or after July 6, 2004"; it names no roof work, and its sections 84-5 and 84-11 keep in force building code ordinances adopted on or before July 1, 1999 that equal or exceed the Code. A search of the whole Township Code for "roof" and for "reroofing" found no section that requires or exempts a permit for roof work, and Chapter 98 (Fees), Chapter 166 (the 2015 International Property Maintenance Code) and the Township's Zoning Ordinance 2026-02 name none. The Township's "Do I need a permit to..." sheet, read from its rendered page, marks a permit for sheds, decks, carports, pools, fences, solar panels and additions and none for new windows or a new garage door; it has no line for roofing. The Township's residential building permit packet lists New Building, Addition, Alteration, Repair, Demolition and Renovation among its types of work and says "NO WORK SHALL BEGIN UNTIL A BUILDING PERMIT HAS BEEN ISSUED"; it names no roof work as a permit type. The Building/Permitting page says "Performing work without a permit will result in the doubling of all permit fees." 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 Technicon Enterprises (610-286-1622) or the Township office (610-929-5324) before starting. Read for this answer: the Township's Building/Permitting page, its permit check sheet and residential building permit packet, its Zoning Ordinance 2026-02, and Township Code Chapters 84, 98 and 166 with the Code's search results for "roof" and "reroofing." The page lists a $50 residential application fee and says the balance is Technicon's review and inspection fees; no full building permit fee schedule was found published.