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, Spring Grove Borough administers the code: Section 175-1 of the Borough Code says "The Borough hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act," the Borough's staff page lists a Building Code Official, and its Building Permit Procedures, issued by its Zoning & Codes Department at 1 Campus Avenue, tell the applicant to make out a check "payable to Commonwealth Code for the total of the inspections and plan review fees" and to "contact Commonwealth Code directly to arrange all building, electrical, plumbing and mechanical inspections." Section 175-2 adopts the UCC by reference as the Borough's building code and the chapter names no edition of the International Residential Code, and the Borough's pages name none.
Permit process
Spring Grove Borough's code and forms read for this record do not say in one voice whether a house reroof needs a permit. Article I of Chapter 175 of the Borough Code (read October 12, 2026) says "The UCC is hereby adopted and incorporated herein by reference" and names no edition. Article II of the same chapter, Permits, dates from Ord. No. 2-1957, and Section 175-11A says "It shall be unlawful for any person, firm, association or corporation to erect, construct, enlarge, alter, repair, move, remove or demolish any building and/or structure within the limits of the Borough of Spring Grove, York County, Pennsylvania, without a permit." Section 175-11B titles that permit "renovation/demolition permit," and Section 175-11C says "The permit required pursuant to this section is required only in the event no permit is required by Article I." Section 175-12 defines "REPAIR" as "Those repairs or replacements identified as exempted from permitting requirements by § 403.62 of the UCC regulations, or such other comparable provisions of those regulations," and Section 175-22B says "No fee shall be required for maintenance or for repairs as defined in § 175-12." The chapter names no roof work. This record does not decide whether a house reroof is a repair as Section 175-12 defines it, or whether the Section 175-11 permit reaches it. The Borough's Zoning Permit Procedures say "A Zoning Permit application is used for all items NOT falling under the PA UCC Building Code," and the Borough's Application for Zoning Permit, headed "USE THIS FORM FOR ALL PA UNIFORM CONSTRUCTION CODE EXEMPT PROJECTS," lists "Roof Replacement*" among its types of work beside siding, windows and gutters, with the note "*MUST MEET THE EXEMPTION REQUIREMENTS OF PA ACT 45 UCC, OR A BUILDING PERMIT APPLICATION IS REQUIRED." The Borough's zoning chapter, Section 400-54B, says "Ordinary repairs and maintenance to existing structures shall not by themselves be regulated by this Zoning Chapter. Examples of such work include replacement of a roof or porch that does not involve enclosure of space. However, such activity may be regulated by the Borough's Building Code." The Borough's Building Permit Procedures say "A Building Permit application is used for all items falling under the PA UCC Building Code," and its building permit application lists no roofing type of work. Both procedures say "IF YOU ARE NOT 100% SURE PLEASE CALL THE OFFICE." 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." Ask the Borough office (717-225-5791) before starting. Section 175-25 sets "a penalty of not more than $1,000, and the costs thereof" for violating Article II, and Section 175-9 sets a fine "of not more than $1,000, plus costs of prosecution" for violating Article I or the UCC. Read for this answer: Chapter 175 of the Borough Code, Building Construction, in full (Article I, Uniform Construction Code, and Article II, Permits); Section 400-54 of the zoning chapter; both pages of an eCode360 search of the whole Borough Code for "roof" and a search for "reroofing," which found no other permit provision naming roof work; the Borough's staff, contact and General Borough Forms pages; its Building Permit Procedures and application, Zoning Permit Procedures and application, and Renovation-Demolition Permit application. The Borough's fee resolution was not found on its site.