**INDUSTRY UPDATE** North Carolina Licensed HVAC Contractors: House Bill 243

New Law Temporarily Lowers R-Values for Duct Insulation to R-4.2

Governor Roy Cooper signed this legislation yesterday, March 17, 2022

House Bill 243 – Duct Notice 3-17-2022


This new law temporarily changes the Commercial and Residential insulation R-value for ducts installed in ventilated and nonventilated non-conditioned spaces (crawlspaces and attics). 

Based on this legislation, contractors can install ducts in Residential ventilated and non-ventilated unconditioned spaces (crawlspaces and attics) with a minimum of R-4.2 insulation. This law will allow for reduced duct insulations values for a period of two years and is now in effect.

  • Any changes in duct insulation values must be included in your load calculation
  • If you are questioned by an inspection department in reference to the duct R-values, please refer them to House Bill 243
  • That actual language for this legislation can be viewed at the following link:  https://www.ncleg.gov/BillLookUp/2021/h243
  • Once you click on the link, you will need to click on “SL 2022-6” in the tool bar on the left side of the webpage. The duct work language is on pages 46 – 47
  • For changes to commercial projects please see the specifics in this legislation