Township of Trowbridge - Building Permits

Township of Trowbridge, Michigan (Allegan County)

city

913 M-40 South, Allegan, MI 49010

Required

Required

In Trowbridge Township a building permit is obtained through Professional Code Inspectors (PCI): the township's Forms & Permits page lists "Building / Electrical / Mechanical Permits" with "Professional Code Inspectors (PCI)" of Dorr, MI, phone 1.616.877.2000, and PCI's own page lists its Dorr office at 1575 142nd Street, Dorr, MI 49323 and Trowbridge Township among its municipalities served. PCI's requirements sheet says an application must come with "A COMPLETED BUILDING PERMIT APPLICATION" and "3 SET OF PLANS OR BLUEPRINTS FOR ALL BUILDING PROJECTS", and it lists Trowbridge Township among the municipalities where "YOUR ZONING MUST BE APPROVED BEFORE SUBMITTING APPLICATIONS", with the township's number given as 269-377-6693. The township's fee sheet lists a zoning compliance permit at $50.00. Neither the township's pages nor PCI's requirements sheet or application mention roofing, and no building permit fee schedule is posted on the township's page, so ask PCI for the current fee.

2015 Michigan Residential Code. This is state law and it is the same in every Michigan city, village, township and county: the state construction code act says "This act and the code apply throughout the state," and the Michigan Residential Code rule adopts "the international residential code, 2015 edition" with the state amendments in R 408.30500 to R 408.30547g. A 2021 edition was filed with the secretary of state in 2025 but has not taken effect. On July 7, 2025 the Michigan Court of Claims entered a stipulated order in Home Builders Assoc et al. v LARA et al., and the Michigan Department of Licensing and Regulatory Affairs (LARA) says that while that order remains in place "the 2015 versions of the IRC and residential provisions of the IECC standards currently adopted, in part, by each rule set will remain valid and in effect." LARA's Statewide Jurisdiction List names the Township of Trowbridge as its own building code enforcer. Township Ordinance No. 2018-2 (adopted 6/7/18) says "the Township of Trowbridge has assumed responsibility for the administration and enforcement of the State Construction Code" and designates violations of it as municipal civil infractions; it names no code edition, and neither the township's Forms & Permits page nor the permit office's requirements sheet and application names a residential code edition.

Required — Required on asphalt shingle roofs by state law. Michigan makes no amendment to the drip edge rule of the 2015 International Residential Code, Section R905.2.8.5, which applies as published: "A drip edge shall be provided at eaves and rake edges of shingle roofs." Segments overlap by at least 2 inches, the drip edge extends at least 1/4 inch below the roof sheathing and at least 2 inches back onto the deck, it is fastened at no more than 12 inches on center, and underlayment goes over it at the eaves and under it at the rakes. A reroof is held to the same rule, because "Materials and methods of application used for re-covering or replacing an existing roof covering shall comply with the requirements of Chapter 9" (R908.1). Township Ordinance No. 2018-2, the permit office's requirements sheet and building permit application, and the township's Forms & Permits page were read for a local rule and state nothing further on drip edge. About drip edge

Required — Required everywhere in Michigan by state law. Michigan fills in the climatic design table of the 2015 code once for the whole state (Rule 516, Table R301.2(1)), and its ice barrier underlayment column reads Yes. The state footnote calls for Yes "for areas where the average daily temperature in January is 25 degrees Fahrenheit" or less, or where ice damming has caused damage. The base code then requires an ice barrier "for asphalt shingles, metal roof shingles, mineral-surfaced roll roofing, slate and slate-type shingles, wood shingles and wood shakes," running "from the lowest edges of all roof surfaces to a point not less than 24 inches (610 mm) inside the exterior wall line of the building" (R905.1.2). Detached accessory structures without conditioned floor area are exempt. On a tear-off, an existing ice barrier that is adhered to the deck may stay and be covered with an additional layer (R908.3, Exception). Township Ordinance No. 2018-2, the permit office's requirements sheet and building permit application, and the township's Forms & Permits page were read for a local rule and state nothing further on ice barrier. About ice & water barrier

Not required — No impact-resistance requirement under state law. The 2015 Michigan Residential Code was searched in full and has no hail or impact rating rule for roof coverings: the words hail, impact and UL 2218 do not appear in it, and none of them appears in the roof assemblies chapter of the base 2015 International Residential Code either. Michigan applies one code statewide ("This act and the code apply throughout the state."), and the act gives the power to amend it to the state director, who adopts the model codes "with amendments, additions, or deletions as the director determines appropriate." Township Ordinance No. 2018-2, the permit office's requirements sheet and building permit application, and the township's Forms & Permits page were read for a local rule and state nothing further on impact resistance.

Trowbridge Township and its permit office, Professional Code Inspectors (PCI) of Dorr, publish no size or dollar line below which roof work needs no permit, and neither says anything about reroofing: the township's Forms & Permits page lists "Building / Electrical / Mechanical Permits" with PCI, PCI's requirements sheet asks for "A COMPLETED BUILDING PERMIT APPLICATION" and "3 SET OF PLANS OR BLUEPRINTS FOR ALL BUILDING PROJECTS", and PCI's application offers project types such as new building, addition and "ALTERATION" with no roofing line. Under state law, "before construction of a building or structure, the owner, or the owner's builder, architect, engineer, or agent, shall submit an application in writing to the appropriate enforcing agency for a building permit" (MCL 125.1510(1)), construction includes "the construction, erection, reconstruction, alteration, conversion, demolition, repair, moving, or equipping of buildings or structures" (MCL 125.1502a(n)), and "A building permit is not required for ordinary repairs of a building or structure." (MCL 125.1510(7)), without a definition of ordinary repairs. The general clause supplies the requirement, so plan on a building permit for a reroof in Trowbridge Township and confirm with PCI at 616-877-2000.

Two layers at most, under state law. Michigan builds one- and two-family homes to the 2015 Michigan Residential Code, which adopts the 2015 International Residential Code and makes no amendment to its reroofing section, Section R908; the Michigan rule set was searched in full and R908 does not appear in it. The base section therefore applies as the International Code Council publishes it. Section R908.3.1.1 lists the conditions under which a new roof may not be laid over an existing one, and the third is "Where the existing roof has two or more applications of any type of roof covering." One existing layer may be covered once; a roof that already carries two layers is torn off to the deck. The same section also bars covering a roof that is water soaked or too deteriorated to serve as a base, and covering "slate, clay, cement or asbestos-cement tile." Locally, the township's building instrument, Ordinance No. 2018-2 (adopted 6/7/18, the only building-code ordinance listed on its Forms & Permits page), was read in full: it designates violations of the state construction code as municipal civil infractions and sets penalties, adopts no local technical code and amends nothing in Section R908. The township's zoning ordinance (updated 05.19.2026) was searched for roofing rules and has none beyond nonconforming-structure and solar provisions, and the permit office's requirements sheet and application state no layer rule.

State law, from the base code. Michigan makes no amendment to the roof sheathing section of the 2015 International Residential Code, Section R803, which does not appear in the Michigan rule set, so it applies as published. Lumber roof sheathing follows Table R803.1: over rafters or beams 24 inches apart it must be at least 5/8 inch net thick. Wood structural panels must be identified "for grade, bond classification and performance category by a grade mark or certificate of inspection issued by an approved agency," and their spans may not exceed "the values set forth in Table R503.2.1.1(1), or APA E30." For a shingle roof the base code adds that "Asphalt shingles shall be fastened to solidly sheathed decks" (R905.2.1), and on any reroof "The structural roof components shall be capable of supporting the roof covering system" (R908.2). Township Ordinance No. 2018-2, the permit office's requirements sheet and building permit application, and the township's Forms & Permits page were read for a local rule and state nothing further on roof sheathing.

6%, statewide, with no local add-on. This is state law: the General Sales Tax Act sets the tax "equal to 6% of the gross proceeds of the business," the Use Tax Act sets "a total combined rate equal to 6%," and the Michigan Department of Treasury says "Michigan does not allow city or local units to impose sales tax." On a roofing job the roofer is the taxpayer on materials, because the Use Tax Act counts as a consumer "A person acquiring tangible personal property if engaged in the business of constructing, altering, repairing, or improving the real estate of others." Nothing on the Trowbridge Township Forms & Permits page changes this.