Envelope Performance Loopholes under the ECCCNYS-2025
How Thermal Bridging and Air Leakage Affect Code Compliance and Real-World Building Performance
Sponsored by NYSERDA
The 2025 Energy Conservation Construction Code of New York State (ECCCNYS) introduces important changes to how building envelope performance is evaluated, particularly regarding thermal bridging and air leakage. While traditional compliance methods have focused primarily on insulation R-values and assembly U-factors, the new code recognizes that thermal bridges and uncontrolled air leakage can significantly reduce actual building performance.
This course examines the building science behind the 2025 ECCCNYS envelope requirements and explains how thermal bridging is addressed within the updated code. Participants will review component R-value and assembly U-factor compliance paths, learn how thermal bridge performance derating is calculated, and understand where thermal bridging must be documented for compliance.
The course also explores the impacts of air leakage on energy use, occupant comfort, and building durability, providing practical guidance for designers seeking to improve envelope performance while meeting code requirements.
Photo courtesy of NYSERDA
Originally published in Architectural Record
Originally published in April 2023
LEARNING OBJECTIVES
- Learn the building science behind 2025 ECCCNYS code requirements.
- Differentiate thermal performance requirements of the component R-value method and assembly U-factor method in 2025 ECCCNYS.
- Describe thermal bridging and where it is tracked in 2025 ECCCNYS.
- Explain how thermal bridging impacts building energy performance and thermal comfort.
- Define the impacts air leakage has on building energy performance, durability, and comfort. 6. Understand compliance methods and calculation procedures for thermal bridge performance derating under 2025 ECCCNYS.
