Minnesota Residential Code

Minnesota has one State Building Code, adopted by the DLI commissioner by rule (Minn. Stat. 326B.106). It is a set of rule chapters. Chapter 1300 covers administration for all of them: permits, inspections, and the building official. Chapter 1305 is the Minnesota Building Code (2018 IBC), and chapter 1309 is the Minnesota Residential Code. The current set, called the 2020 Minnesota State Building Code, took effect March 31, 2020 (the Minnesota Mechanical and Fuel Gas Code followed on April 6, 2020).

Minn. Rules 1309.0010 incorporates the 2018 International Residential Code (IRC), published by the International Code Council, by reference. It is made part of the State Building Code except as qualified by chapter 1300 and as amended in chapter 1309. Part 1309.0010 lists the mandatory IRC parts that any municipality enforcing the code must administer: chapters 2 to 10 and 44, section P2904 of chapter 29, and Appendices K and Q. The other IRC appendices are deleted. IRC chapter 1 (administration) is replaced by chapter 1300. The IRC's energy, mechanical, fuel gas, plumbing, and electrical chapters are not among the mandatory chapters. Minnesota regulates those through its own codes: the Minnesota Energy Code, the Minnesota Mechanical and Fuel Gas Code, the Minnesota Plumbing Code (ch. 4714), and the Minnesota Electrical Code (the NEC, ch. 1315).

The State Building Code applies statewide. Under Minn. Stat. 326B.121, subd. 1, it is the standard for the construction, reconstruction, alteration, repair, and use of the buildings it governs, and it supersedes the building code of any municipality. A city may not, by ordinance or development agreement, require building code provisions that differ from the State Building Code. Cities can still regulate zoning, setbacks, and similar land use matters.

Enforcement is local. Under 326B.121, subd. 2, a municipality that had an ordinance adopting the State Building Code in effect on Jan. 1, 2008 must keep administering and enforcing it and may not repeal that ordinance. Other municipalities may choose to enforce it by adopting it by ordinance. If the commissioner determines that a municipality is not properly administering and enforcing the code, the commissioner may have the state building official, or another building official certified by the commissioner, take over administration and enforcement there. In areas with no local enforcement, the code still legally applies, but there may be no building permit or inspection for a house. DLI handles public buildings and state-licensed facilities in those areas. Lenders and insurers may still require compliance, and electrical and plumbing rules apply statewide on their own terms.

Next edition: DLI is updating the Minnesota Residential Code to the 2024 IRC. The Residential Code Technical Advisory Group (TAG) met twenty times, reviewed chapters 2 to 10 of the 2024 IRC, and recommended adopting it with Minnesota changes (DLI's 2024 model codes review report, 2025). DLI published a Request for Comments in the State Register on Feb. 2, 2026 for amending chapter 1309 to incorporate the 2024 IRC. A Request for Comments is the first formal step in rulemaking, not an adoption. This page could not confirm a proposed or adopted effective date. Until one is announced, the 2018 IRC-based code applies. Check DLI's rulemaking docket for chapter 1309.

Minn. Rules 1300.0120, subp. 1 requires an owner or authorized agent to apply to the building official and get the required permit before constructing, enlarging, altering, repairing, moving, demolishing, or changing the occupancy of a building or structure, or before having that work done. This applies in areas where the State Building Code is enforced.

Subpart 4 lists the work exempt from a building permit, and Minnesota's list is not the same as IRC R105.2. Examples include one-story detached accessory structures used as tool and storage sheds, playhouses, and similar uses, if the floor area is 200 square feet or less. Also exempt are decks and platforms not more than 30 inches above adjacent grade, not attached to a structure with frost footings, and not part of an accessible route. A deck attached to a house, or one more than 30 inches up, needs a permit. An exemption from the permit never authorizes work that violates the code or any other law or ordinance, so an exempt deck must still be built to code. Zoning permits are a separate question for the city.

Inspections come from Minn. Rules 1300.0210. Work must remain accessible and exposed for inspection until approved. Work may not go beyond the point indicated in each successive inspection without the building official's approval. Rough-in inspections of plumbing, mechanical, gas, sprinklers, alarms, and electrical systems are made before covering or concealment, before fixtures or appliances are set, and before the framing inspection. The framing (framing and masonry) inspection is made after the roof, masonry, framing, firestopping, draftstopping, and bracing are in place, and after the plumbing, mechanical, and electrical rough inspections are approved. Any portion that does not comply must be corrected and may not be covered or concealed until the building official authorizes it. Hanging drywall or insulation over framing that has not passed its inspection is a violation even if the framing is perfect.

Permits expire. Under 1300.0120 (see the expiration subpart), a permit expires if the authorized work has not started within 180 days after issuance, or becomes invalid if the work is suspended or abandoned for more than 180 days after it has started. The building official can grant written extensions of up to 180 days each when the permit holder shows justifiable cause.

Contractor licensing is separate from the permit. A person in the business of building or improving residential real estate for an owner, providing two or more 'special skills', needs a residential building contractor or residential remodeler license from DLI (Minn. Stat. 326B.802 and 326B.805). The special skills are excavation, masonry and concrete, carpentry, interior finishing, exterior finishing, drywall and plaster, residential roofing, and general installation specialties. Exemptions include a contractor who provides only one special skill and a contractor with a certificate of exemption whose gross annual receipts from that work do not exceed $15,000. Residential roofers have their own licensing rules.