Skip to main content

NGA Publishes New Paper on Energy Conservation Codes

Glass Technical Paper addresses ASHRAE 90.1 and the IECC

NGA has published a new Glass Technical Paper (GTP), Alignment in U.S. Energy Conservation Codes: ASHRAE 90.1 and the IECC. This paper provides information on the codes’ use as national model codes, and their compliance paths for commercial and residential buildings, both new construction and existing buildings.

“In representing the interests of the glazing industry on these various energy code committees, we are always looking into the future – in fact, we are already working on development of codes for 2024 and 2025,” explains Tom Culp, Birch Point Consulting and NGA energy code consultant. “At the same time, it is equally important that we help educate the industry about the results of those efforts as the energy codes and standards are implemented in the real world today, and NGA’s new Glass Technical Paper will be a good resource for the industry.”

The GTP further expands upon prescriptive versus performance path requirements, and how it relates to the increased demands placed on glazing systems to achieve certain stringencies based on evolving climate zone maps. U-factors and Solar Heat Gain Coefficients (SHGC), and an estimation of glazing required, are also charted by climate zone for both commercial and residential vertical fenestration paths.

The complimentary GTP is available among a host of additional resources in the NGA Store at

Also, download the related GTP, Building Energy Performance Criteria Terms and References Related to Glass and Glazing, and view complimentary webinar recordings related to energy performance produced by NGA under On-Demand Webinars.

Download the new Glass Technical Paper