Thermal Bridging Calculation Procedures under the ECCCNYS-2025  

As energy codes become more stringent and building enclosure performance expectations continue to rise, accurately accounting for thermal bridging is essential to high-performance building design. With the adoption of the Energy Conservation Construction Code of New York State (ECCCNYS-2025), design teams must understand how thermal bridge impacts influence assembly performance calculations and overall code compliance. While insulation levels and clear-field assembly values remain important, heat loss through transitions, penetrations, interfaces, and structural connections can significantly impact overall envelope performance, condensation risk, occupant comfort, and energy efficiency.

This webinar examines practical calculation procedures for assessing the impacts of thermal bridging in building assemblies, with a focus on understanding and applying clear-field, linear, and point thermal bridge analyses. Presenters will review how Psi-values and Chi-values are used to quantify additional heat flow through common conditions such as shelf angles, balconies, slab edges, cladding attachments, parapets, and other envelope transitions.

The session will introduce calculation methodologies for determining average assembly U-value impacts from thermal bridges and review commonly used analysis tools, software platforms, and supporting resources available to design teams. Dylan Martello, Senior Building Systems Consultant, Passive House Services - CPHD from SWA will also explain how thermal bridge modeling outputs can be interpreted to improve detailing decisions and optimize enclosure performance. Additional discussion will focus on updated thermal bridging calculation procedures, compliance pathways, and documentation requirements incorporated within the ECCCNYS-2025, helping project teams understand how thermal bridge accounting supports energy code compliance and high-performance enclosure design.

Photo courtesy of Stella 16

Dylan Martello, is a Senior Building Systems Consultant and Certified Passive House Designer with Steven Winter Associates, Inc. specializing in Passive House and Net Zero projects. Dylan works with project architects and engineers to assist in the design of extremely energy efficient buildings. His direct project experience on large-scale Passive House certified or pre-certified projects comprises a wide range of use types such as high rise multifamily, core and shell offices, hotels, and industrial facilities.