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, Bern Township's Permits and Licenses page names LTL Consultants, Ltd., One Town Center Drive, Oley, 610-987-9290, as the Township's Building Inspector, Code Enforcement Officer and Zoning Officer, and the Township's building permit packet carries the heading "BERN TWP PERMIT APPLICATION CHECKLIST LTL CONSULTANTS, LTD". Section 68-1 of the Township Code says "Bern Township hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act." Section 68-2 adopts "The Uniform Construction Code, contained in 34 PA Code, Chapters 401 through 405, as amended from time to time" as the building code of Bern Township, and Section 68-5A keeps building code ordinances adopted "on or before July 1, 1999" that equal or exceed the code in force. Section 68-2 adopts the Uniform Construction Code "as amended from time to time," Section 68-6.2 adopts Section R105.2 of "the International Residential Code of 2003," 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 to a house.
Permit process
Bern Township's code speaks to reroofing in two places that answer a full reroof differently. Section 68-6.1 of the Township Code (Ord. No. 217-2005, February 1, 2005) requires permits for "All alterations or repairs to residential buildings which are exempt from the UCC by Act 92 of 2004," except nine listed kinds of work that "shall continue to be exempt and no permit will be required," the second of which is "Reroofing of less than 25% of the total existing roof square footage." Section 68-6.2 of the same chapter (Ord. No. 215-2004, November 1, 2004) amends the Act's section 104 exclusion for the Township and says "The Township shall not require permits for the following: (i) roof covering replacement," while requiring permits for renovations and repairs that involve "structural modification." Both sections are in the current Township Code. The Department of Labor and Industry's register of municipal code change ordinances lists a Bern Township filing that "Requires a building permit for all residential alterations and repairs, and establishes 9 exceptions," found in compliance with an approval letter mailed January 26, 2005, "Enacted 2 / 1 / 05." The Township's building permit packet and its 2024 zoning and building permit fee resolution (a scanned document, transcribed from the rendered page images) name no roof work; the residential fee for "Renovations, Alterations, Modification, and where none of the above categories apply" is charged by square foot of building area. 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 of a municipal ordinance that adds to the code, section 503(c) says "An ordinance under this subsection shall not be effective nor enforceable unless subsections (d), (e), (f), (g), (h) and (i) have been satisfied." 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." The two sections of Chapter 68 answer an ordinary full reroof differently, and the Township's office pages say nothing on roof work, so this record does not decide whether the Township requires a permit for one. Ask LTL Consultants at 610-987-9290 before work starts. Section 68-7 makes a violation "a summary offense punishable by a fine of not less than $100 nor more than $1,000." Applications go to the Township with an $80 application fee and a stormwater application (all projects except fences) on the Township's zoning and building permit application, which asks for the contractor's PA Contractor Registration number and proof of workers' compensation insurance. The Township office, 610-926-2267, is open Monday to Thursday, 8:30 a.m. to 4:30 p.m., and Friday, 8:30 a.m. to 12 p.m. Read for this answer: Chapter 68 of the Township Code (Construction Codes, Uniform, Sections 68-1 to 68-10), Chapter 8 (Code Enforcement) and Chapter 81 (Fees) in full; every page of a search of the whole Township Code for "roof" and for "reroofing"; the Permits and Licenses page; the 2023 building permit packet; and the 2024 zoning and building permit fee resolution.