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, Section 5-101 of the Borough Code (Ord. 1375, 2010) says "The Borough of Gettysburg hereby elects to administer and enforce the Uniform Construction Code," and the Borough's Permits and Licenses page says "The Borough of Gettysburg administers and enforces the Uniform Construction Code (UCC) with the assistance of our colleagues at the Pennsylvania Municipal Code Alliance (PMCA)," that applications for projects requiring UCC permits "are forwarded to PMCA for plan review and inspection(s)," and that "Projects exempt from UCC permits are processed in-house by the Planning Department" at 59 East High Street. Chapter 5 adopts the Uniform Construction Code "as amended from time to time" and names no code edition, Section 5-105 says "All relevant ordinances, regulations and policies of the Borough of Gettysburg not governed by the Code shall remain in full force and effect," and the Borough's permit pages name no code edition. Chapter 5 changes nothing in the code's roofing provisions.
Permit process
The Borough of Gettysburg lists residential roof replacement not involving framing as work needing its own non-UCC building permit, a local permit separate from a UCC building permit. The Borough's Consolidated Land Use Permit Application (read October 9, 2026) lists among "Examples of work that require a non-UCC building permit" "Residential (single or 2-family) roof replacement/repair not involving repair or replacement of framing," and says "Non-UCC building permits are issued for work that does not require review, permitting, and inspection through the PA Uniformed Construction Code (UCC)." It prices the "NON-UCC BUILDING PERMIT: $12 PER $1,000 IN COST UP TO $10,000 (MAX $120 PERMIT FEE)" on top of a $40 Land Use fee, and gives "Replace existing asphalt shingle roof with standing seam metal in red" as an example scope of work. The Permits and Licenses page says the Consolidated Land Use Permit "is required for all proposed projects within the Borough" and that "All residential work requires a Land Use Permit." Its examples of work that requires a UCC building permit include "Structural repair or change to any building, including 1-2 family residences." So the permit the Borough's own pages name for a house reroof that leaves the framing alone is the Borough's non-UCC building permit, issued with its Land Use Permit, which the application itself describes as for work that does not require permitting through the Uniform Construction Code; roof work involving repair or replacement of framing falls outside that line. In the Gettysburg Historic District, the Permits and Licenses page also says "Any proposed alterations to properties located in the Gettysburg Historic District must be granted a Certificate of Appropriateness (COA) before work may begin." Chapter 5, Part 1 of the Borough Code adopts the Uniform Construction Code with no amendment touching roof work, and a search of the whole Borough Code for "roof" and "reroofing" found no section naming a permit for roofing. The Borough's Zoning chapter, Section 27-112 (Ord. No. 1498-25, December 8, 2025), says "A building permit shall be obtained from the Zoning Officer, or designee, for any construction, addition, alteration, relocation, or conversion or removal or demolition of any building or structure," and names no 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 decide whether a UCC building permit is needed for a house reroof here. In practice, expect the Borough to require a Land Use Permit and its non-UCC building permit before a house is reroofed, and a UCC building permit through PMCA where framing is repaired or replaced. Section 27-111 of the Zoning chapter says that where a zoning permit is required but work starts before it is obtained, "the fees set by ordinance or resolution of the Borough Council for such permit shall be doubled." Applications, with the fee by check or money order payable to the Borough of Gettysburg, go by email, by mail or to the drop box at the Borough office, 59 East High Street, Gettysburg, PA 17325; the Borough's number is 717-334-1160. Read for this answer: Chapter 5 of the Borough Code (Part 1, Uniform Construction Code, Sections 5-101 to 5-107, and Part 2, Property Maintenance Code) and Chapter 4, Buildings, in full; Sections 27-111 and 27-112 of the Zoning chapter; every page of a search of the whole Borough Code for "roof", "reroofing" and "building permit"; the Permits and Licenses page; and the Consolidated Land Use Permit Application with its fee schedule.