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, The Borough of Nazareth administers the code through Barry Isett & Associates, Inc.: Section 5-101 of the Borough Code says the Borough "hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act," Section 5-103 provides for "the retention of one or more construction code officials or third = party agencies to act on behalf of the Borough of Nazareth," and the Borough's Zoning page says "Barry Isett & Associates, Inc. administers all of the Zoning and Building Code Services (PA UCC) for the Borough of Nazareth." Section 5-102 adopts the Uniform Construction Code "as amended from time to time" and incorporates it by reference "as the municipal building code of the Borough of Nazareth," and Chapter 5 changes nothing in the code's roofing provisions. Neither Chapter 5 nor the Borough's pages name a code edition.
Permit process
No Borough of Nazareth text read names reroofing as permit work or as exempt. The Borough's permit information sheet, "WHAT TYPE OF PERMIT(S) DO I NEED?" (read October 9, 2026), lists the residential work that needs a zoning permit, a building permit or both, from decks and porches through "Alterations that involve structural changes" and the removal or cutting of structural members, and does not list roof replacement either way. It says "If you are uncertain, always contact the Building Code Official (BCO) and the Zoning Officer to confirm permitting requirements prior to proceeding with your project." Part 1 of Chapter 5 of the Borough Code, Adoption of the Uniform Construction Code (Ord. 614, as amended through Ord. 697 of June 7, 2004), adopts the Uniform Construction Code "as amended from time to time" and adds no permit clause and no roof words of its own. The Borough's 2026 fee schedule lists a UCC application fee and says "All other UCC fees, including, but not limited to, building, electrical, mechanical, plumbing, etc. are set forth on the Barry Isett fee schedule"; it has no roofing line, and the published copy does not include that schedule. 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." Because the Borough's only general permit clause is the state code's own, adopted by reference, and neither the Borough nor its agency has published a statement on reroofs, this record does not decide whether the Borough requires a permit for an ordinary reroof. The information sheet also says "doing work regulated by the Uniform Construction Code (UCC) without a permit will result in an enforcement action being taken against you by the municipality." Completed applications go to the Borough of Nazareth Administration Office at 134 S. Main St., and the Zoning page says "Building Permits may require additional fees and original copies so please check with the BCO for specific instructions." Borough offices are open Monday through Friday, 8:30am to 4:30pm, at 610-759-0202. Read for this answer: Part 1 of Chapter 5 of the Borough Code (Sections 5-101 to 5-106), in full; every page of a search of the whole Borough Code for "roof" and for "reroofing," which found no permit provision naming roof work; the Borough's Zoning, Forms & Documents and Contact pages; the permit information sheet; the Application for PA UCC Construction Permit and the Application for Zoning Permit the Borough posts; and the 2026 fee schedule.