2021 International Energy Conservation Code

• The 2021 International Energy Conservation Code® (IECC) is a model code developed by the International Code Council (ICC) that establishes minimum energy efficiency requirements for both residential and commercial buildings. It is designed to reduce energy consumption, lower utility costs, and limit greenhouse gas emissions through more efficient building systems and construction practices. This edition represents one of the most ambitious updates to the IECC, with increased emphasis on performance, renewable energy, and long-term sustainability.
• Key Aspects:
  • Enhanced Energy Efficiency
  • Improved Building Envelope Requirements
  • Mechanical System Improvements
  • Solar-Ready and Electrification Provisions
  • Commercial Lighting and Controls
  • Residential Updates
  • Performance and ERI Path Improvements
  • Sustainability, Grid Readiness & Resilience
• Highlights:
  • The 2021 IECC is approximately:

• 9–14% more efficient than the 2018 IECC (depending on climate zone and building type).
• Over 40% more efficient than the 2006 IECC baseline.

Stricter ERI score targets (e.g., HERS Index ≤57–62 depending on climate)

About ICC

International Code Council is a leading organization dedicated to developing a single set of comprehensive, coordinated national model construction codes. To date, 48 U.S. states have adopted various international codes from the International Code Council.

Other Works:

• 2012 International Fuel Gas Code
• 2018 International Mechanical Code
• 2021 International Building Code