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, Dillsburg Borough takes permit questions at its Borough office, 233 S. Chestnut St., and its Building/Zoning Permit Information page posts building permit application checklists for decks, swimming pools and demolition, the deck checklist under the letterhead of a code services firm, Approved Code Services, of Mechanicsburg. The Borough's 2026 fee schedule lists a "3rd Party Building Inspection and Plan Review Fee" of "As established by 3rd party administrator" and a "State Fee" of $4.50. The Borough's code of ordinances is posted at codelibrary.amlegal.com, which returned an access-denied response to every read this record made, so no Borough ordinance adopting the Uniform Construction Code, and no Borough building permit chapter, was read for this record. The Borough's Ordinances page posts a short "Common Ordinances" summary, a rental inspection list and a pending 2025 ordinance, none of which names roof work. None of the Borough pages, forms or fee schedule read for this record names a code edition.
Permit process
Dillsburg Borough's pages do not say in terms whether a house reroof needs a building permit. The Borough's Ordinances page says "A building permit is needed before any new construction is started in the Borough. Permits are also needed for many remodeling, refurbishing and repairing projects. Please check with the Borough Office to see if a building permit is required" (read October 12, 2026). Its 2026 fee schedule (a scan, read from the rendered page) lists, under "Building Permit Fees," a "Roof Repair" line at $35.00 beside "Window Replacement" and "Door Replacement" lines at $35.00 each, and a "Building Permit" line of "$7.50 per $1000 cost per estimated value ($35 minimum) plus inspection." The fee schedule names no reroofing or roof replacement line, and this record does not decide whether a house reroof is a "Roof Repair" under that line. The Borough's code of ordinances is posted at codelibrary.amlegal.com, which returned an access-denied response to every read this record made, so no Borough ordinance adopting the Uniform Construction Code, and no Borough building permit chapter, was read for this record. The Borough's Ordinances page posts a short "Common Ordinances" summary, a rental inspection list and a pending 2025 ordinance, none of which names roof work. 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 Borough requires a permit for a house reroof; ask the Borough office (717-432-9969, Monday to Friday, 7:00 a.m. to 3:30 p.m.) before starting. Read for this answer: the Borough's home, Staff, Forms, Ordinances and Building/Zoning Permit Information pages; its 2026 fee schedule; its deck, swimming pool and demolition checklists; its rental inspection list and plan submission sheet; and the Ordinances page's posted ordinance PDFs (the "Common Ordinances" summary and the 2025 ordinance, one a scan).