The Model Low Energy and Carbon Code (MLECC) is an enhanced energy standard in Colorado designed to push building efficiency beyond baseline requirements. It serves as a framework for low-energy and low-carbon construction in both new homes and major renovation projects.

Key aspects of the MLECC include:

• Carbon Reduction: It specifically targets lower carbon emissions and moves projects toward net-zero energy readiness.
• Foundation: The code is built upon the International Energy Conservation Code (IECC) standards published by the International Code Council, adding stricter performance criteria.
• Strict Requirements: The code introduces more rigorous standards for thermal envelopes, enhanced air sealing, and electric-ready provisions for future electrification.
• Performance Benchmarks: It sets specific thresholds for building components, such as requiring R-49 attic insulation and R-20 wall insulation (with continuous insulation) in many jurisdictions, as well as high-performance windows that meet Energy Star 2026 standards.

While the MLECC establishes a statewide baseline, local adoption varies by jurisdiction. For example, Denver and Centennial expect mandatory compliance by 2026, while Colorado Springs has delayed adoption until 2027.

• Model Low Energy and Carbon Code Mlecc Colorado: Essential Guide