The 2015 IECC with North Carolina specific amendments went into effect on January 1, 2019. Below is a summary of changes to the building envelope-related requirements in the updated code for North Carolina.
Code Change Highlights:
- The Code contains separate Maximum Energy Rating Index scores for those including calculations of on-site renewable energy.
- R-19 fiberglass batts compressed and installed in a 2×6 framing cavity will comply. However, R-19 compressed in a 2×4 wall is not deemed to comply.
- Duct insulation requirements were amended as follows: Ducts in unconditioned space must be insulated to R-8, and ducts in semi-conditioned space must be insulated to R-4. Return ducts in conditioned and semi-conditioned space are not required to be insulated. Ducts inside conditioned space are not required to be insulated unless to prevent the formation of condensation.
Energy-Efficient, Cost-Effective Construction with Fiberglass and Mineral Wool Insulation
As code levels advance, keep informed about innovative practices to meet or exceed code requirements using cost-effective fiberglass and mineral wool insulation. The following resources are just a subset of the many guides available from the Insulation Institute to help you achieve new performance requirements with proven approaches.
- Air Leakage: As states adopt more stringent energy codes, some builders may experience challenges meeting new mandatory air leakage requirements. Fiberglass and mineral wool insulation is the low-cost solution for homebuilders to meet or surpass code air leakage rate requirements of 3 or 5 air changes per hour depending on climate zone. For homeowners, an airtight building envelope results in energy savings and increased thermal comfort.
- Ducts Buried Within Ceiling Insulation: Deeply buried ducts in attics is an easy way to lower energy code compliance costs for builders using the simulated energy performance path. Homeowners can benefit from energy savings realized from lower-capacity, lower-cost HVAC systems.
- Proper Installation of Insulation: Grade I installation delivers superior energy efficiency and is increasingly required by state energy codes. Insulation installation jobs that fail to meet Grade I criteria can mean construction delays due to callbacks, HERS rating penalties, and failed code inspections. Grade I installation is readily achievable by following basic guidelines as recommended by manufacturers. NAIMA offers free online training for installers.
- Unvented Attics Using Fiberglass and Mineral Wool Insulation: Unvented attics can be constructed by installing fiberglass or mineral wool insulation below the roof deck instead of using more costly materials like spray foam. In addition, fiberglass and mineral wool insulation products are green certified and do not carry recommended occupancy restrictions due to product off-gassing after installation. Starting with the 2018 IRC, this practice is outlined in detail within the code. Homeowners benefit from lower construction costs and the use of a safe product.
To view a listing of key envelope changes in the North Carolina Energy Code, download the detailed summary.
This summary is offered for informational purposes only. It does not purport to be an exhaustive analysis of code changes or provide advice that will ensure guaranteed compliance with any energy code provision. Please consult with local authorities before finalizing your installation plans.Download Now