The 2018 International Energy Conservation Code (IECC) establishes minimum energy efficiency standards for building design and construction across the United States. Adopted by most states and municipalities, this model code applies to residential and commercial buildings, specifying requirements for insulation, air sealing, HVAC equipment efficiency, and fenestration performance.
Technical Standards
IECC 2018 requires SEER 13 minimum for air conditioners in most climate zones and AFUE 90% for gas furnaces. The code mandates duct sealing to 10% of total flow rate and establishes U-factor requirements for windows ranging from 0.30 to 0.57 depending on climate zone. Continuous insulation requirements vary by building type and location.
Practical Implementation
HVAC contractors must ensure equipment meets specified seasonal efficiency ratings and that installation practices comply with duct leakage limits. Energy audits and blower door testing verify code compliance. Many jurisdictions adopted IECC 2018 between 2019 and 2022, making it the current baseline for most new construction projects nationwide.