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, Fermanagh Township elects to administer the code: Section 60-1 of its Code (Ord. No. 2-2026, adopted March 9, 2026, confirming the Township's 2004 election) says the Township "hereby elects to administer and enforce the provisions of the Pennsylvania Construction Code Act, Act 45 of 1999," and Section 60-3 lets the governing body use "one or more construction code officials or third-party agencies." The Township's Contact Us page lists "Building Inspection Underwriters of PA: 877-453-4321" beside its Zoning Officer, and its Permit Application Forms page links "Commonwealth Code Building Applications" and "Building Inspection Underwriters of PA"; the Township's pages do not say which of the two issues a given building permit. The Township Office is at 109 Municipal Road, Mifflintown (717-436-8870), open Monday to Friday 7:00 a.m. to 2:00 p.m. The Township's Code and pages name no code edition; Section 60-2 adopts the code "as amended from time to time," so the text above is the State's current one.
Permit process
Fermanagh Township's own Code and pages name no roof work as permit work or as exempt. Chapter 60 adopts "The Uniform Construction Code, contained in 34 Pa. Code, Chapters 401 through 405, as amended from time to time," "as the municipal building code of Fermanagh Township" in Section 60-2 and, in Section 60-5, keeps in effect building code ordinances adopted on or before July 1, 1999 that equal or exceed the Code; it names no roof work and no code edition, and the Township's pages name no pre-1999 building code ordinance. Chapter 175, Zoning, Section 175-45 A says "It shall be unlawful to commence the excavation for or the construction or erection of any building, including an accessory building, or to commence the moving or alteration of any building, including an accessory building, until the Zoning Officer has issued a building permit for such work. No permit shall be required for repairs to or maintenance of any building, structure or grounds provided such repairs do not change the use or otherwise violate the provisions of this chapter"; that is the Zoning Officer's permit under the zoning chapter, it names no roof work, and this record does not decide whether a house reroof is an "alteration" or "repairs" under it. The Township's Land Use Permit application (read October 10, 2026) asks "Building Permit Required" with Yes and No boxes, and states "Permit Fee: $30.00 for first $1000.00 then $1.00 per thousand after." Neither the application nor the Township's other permit forms name reroofing. 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 Township requires a permit for a house reroof; ask the Township Office (717-436-8870) before starting. Read for this answer: Chapter 60, Construction Codes, Uniform (Sections 60-1 to 60-7), and Chapter 175, Zoning, Article IX (Sections 175-44 to 175-55), in full; every page of a search of the whole Township Code for "roof" (15 results, none a permit provision for roof work) and for "reroofing" (no results); the Township's Building and Permit Information, Permit Application Forms, Ordinances, Officials and Contact Us pages; the Land Use Permit, Driveway Permit and Demolition Permit applications; and the permits and residential code guidelines pages of Building Inspection Underwriters of PA and the home page of Commonwealth Code Inspection Service, which name no roof work.