2.1 The State Construction Code, Permits & Inspections

Where Michigan's Building Rules Come From

The Stille-DeRossett-Hale Single State Construction Code Act (1972 PA 230) authorizes LARA's Bureau of Construction Codes to adopt one statewide code. Local governments enforce it, or the state enforces it where a community has not taken on enforcement. PSI's reference list for this exam includes both the Act and the Michigan Residential Code.

For one- and two-family dwellings and townhouses, the code is the Michigan Residential Code (MRC). Rule R 408.30500 adopts the 2015 International Residential Code, with Michigan amendments, as the MRC. LARA lists the 2015 MRC as the current code, effective February 8, 2016.

LARA filed rules in 2025 to move to the 2021 IRC and 2021 IECC residential provisions, with an effective date of August 29, 2025. On July 7, 2025, the Michigan Court of Claims entered a stipulated order in Home Builders Association of Michigan v. LARA. The order temporarily stops LARA from implementing those rule sets while the lawsuits continue. The 2015 editions therefore remain in effect. The PSI roofing outline also cites the 2015 MRC. Commercial buildings follow a different code: the 2021 Michigan Building Code has been in effect since April 9, 2025.

This guide teaches the 2015 MRC section numbers. If an exam question cites the MRC, use the 2015 rule.

When a Permit Is Required

MRC R105.1 requires an owner or authorized agent who intends to construct, enlarge, alter, repair, move, or demolish a building to obtain a permit from the building official first. R105.2 lists work that does not need a building permit. Examples include small detached accessory structures up to 200 square feet, fences up to 7 feet, painting, papering, tiling, and similar finish work. Reroofing is not on that list.

Other permit rules include:

A small, like-for-like repair may count as an ordinary repair. A tear-off and new roof covering is a repair and alteration of the roof assembly, and most Michigan enforcing agencies require a permit for it. Always check with the local building department. LARA's guidance for homeowners recommends that the contract state the contractor will get all required permits before starting work. MCL 339.2411(2)(e) makes a willful violation of building laws a ground for discipline.

Inspections and Enforcement

The building official inspects permitted work and may approve it, require corrections, or issue a stop work order for unsafe or unpermitted work (R114). Michigan's R113.4 amendment makes it unlawful to perform work that violates the code, the approved construction documents, or a permit, and violators are fined under the Act. Two parts of Article 24 depend on inspections:

• A building inspection report from a state or local building official can verify a homeowner's workmanship complaint (MCL 339.2411(4)(c)).
• Workmanship not meeting the MRC is itself a ground for discipline (MCL 339.2411(2)(m)).

Michigan's Climatic and Geographic Design Criteria

Michigan fills in MRC Table R301.2(1) for the whole state (R 408.30516):

Table R301.2(5) values range from 20 psf (for example, most of Wayne and Hillsdale Counties) up to 90 psf in most of Keweenaw County and 100 psf in three Keweenaw townships. Other examples include Marquette County at 70 psf and Houghton County at 80 psf. Under R301.2.3, buildings where the ground snow load exceeds 70 psf must be designed by accepted engineering practice rather than the code's prescriptive tables. That matters before adding a second roof layer or heavy tile in the Upper Peninsula.

Fire Classification

Michigan amended R902.1. Class A, B, or C roofing is required only in jurisdictions that designate it by law or where the edge of the roof is less than 3 feet from a lot line. Classified roofing must be tested under UL 790 or ASTM E108. Some assemblies count as Class A without testing, such as slate over underlayment on a combustible deck and 16-ounce copper over a combustible deck. Michigan also added R909 for rooftop solar. PV panel systems must follow Section R324 and NFPA 70, be designed for their loads, and have all roof penetrations flashed and sealed.

Which Rule Wins

The PSI bulletin tells candidates how to handle conflicts:

1. A legal requirement, such as a law, rule, or code, overrides any other reference, including a manufacturer's book or trade manual.
2. If two legal requirements conflict, the Michigan-specific law, rule, or code wins over the national one.
3. Among non-legal sources, the listed study materials win over other sources.

So if an NRCA manual and the MRC disagree on a minimum, use the MRC. If a national OSHA rule and a Michigan MIOSHA rule differ, use MIOSHA. Manufacturer instructions still matter, because R904.1 and R905.1 require roof coverings to be installed per the manufacturer's instructions and the code.