Minnesota Insulation Code – A Brief Guide for MN Contractors

Written by Kacie Goff

In 2018, Minnesota launched a new effort. Now, every six years (from the 2018 start date), the state reviews the current model energy codes laid out by the U.S. Department of Energy (DOE), in partnership with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the International Code Council (ICC). Those codes then get amended for integration into Minnesota’s own building code. 

That means key components of the state codes that tradesmen need to know — like the Minnesota energy code and Minnesota insulation code — will likely change every six years. How are you supposed to keep up? 

By catching up to current requirements, then using your continuing education hours to stay informed about current state building codes during each renewal cycle. To start, here are the current Minnesota insulation code requirements. 

What does the Minnesota insulation code require?

Since Minnesota has some of the highest recommended R-values for insulation in the country, it’s critical that you know exactly what’s required where if you’re installing insulation. 

Here are the requirements per the most recent residential Minnesota energy code: 

  • Wood frame wall insulation: R-20 or 13+5 (CZ6), R-21 (CZ7)
  • Foundation or crawl space insulation: R-15 insulation for concrete masonry foundations and R-10 applied to the exterior of the wall; R-10 continuous insulation is allowed on the exterior of the foundation wall if the air leakage rate is below 2.6 ACH50
  • Duct insulation: Depending on the location, R-3.3 to R-8 and vapor or weather retarder might be required
  • Mechanical ventilation: All buildings are required to have a balanced mechanical ventilation system that is +/- 10% of the system’s design capacity 

The changing nature of Minnesota insulation codes can feel like a drag if you work as a contractor. But know that these changes do deliver direct benefits. The DOE has determined that by 2030, making regular adjustments to the Minnesota energy code will deliver energy cost savings of close to $207 million each year. 

By staying up-to-date and complying with Minnesota insulation code whenever it changes, you help homeowners and business owners save significant energy and, as a result, money. 

How can I make sure I stay informed about changes to Minnesota insulation code? 

You’re caught up to speed now, but what happens when the state reviews the model codes and consequently amends the Minnesota energy code in 2024? 

You don’t have to dedicate extra time to stay informed about the latest in Minnesota building code, fortunately. Instead, you can turn to the continuing education hours you’re already required to take. By using hours you have to complete anyway to learn about any changes in the code, you keep yourself informed without overburdening your schedule. 

Because Minnesota contractor licensees are required to take 14 hours of CE per two-year renewal cycle, you might prefer to do a little bit each year. To that end, you can take this seven-hour Department of Labor and Industry (DLI)-approved construction practices package course. Part of the course specifically focuses on the Minnesota energy code.

If you prefer to take all your CE hours at once, you can still brush up on current Minnesota insulation code during it. This 14-hour residential contractor CE package will teach you about current Minnesota energy code requirements. 

All told, using your CE hours, you can stay in the know about the current Minnesota insulation code requirements that apply to you.