Most Efficient Recognition Program Finalized

December 03, 2012

The EPA has finalized its Most Efficient Recognition Program, providing details for the inclusion of the fenestration industry. In 2013, here are the initial performance targets for residential window manufacturers:

1. Products must be ENERGY STAR-qualified consistent with applicable ENERGY STAR Partner Commitments and the requirements set forth in the latest version of the ENERGY STAR Program Requirements Eligibility Criteria for Windows, Version 5.0. Product performance - measured by U-factor and solar heat gain coefficient (SHGC) – must be certified by an EPA-recognized certification body.

2. Products must be certified to meet the North American Fenestration Standard/Specification (NAFS) with a Performance > 15. An EPA-recognized certification body is not required for NAFS certification. For more information about NAFS, visit

3. Products must meet the applicable requirements shown in the table below:

Climate Zone U-Factor SHGC
Northern 0.20 0.20
Northern-Central 0.20 0.40
South-Central 0.20 0.25
South 0.20 0.25

To qualify a product as Most Efficient, fill out an application with supporting documentations to the EPA. Qualified products may use 2013 Most Efficient in its product marketing for as long as the product is available.

With these new requirements, nearly 400 manufacturers have products that meet ENERGY STAR v. 5.0, but the products do not meet the Most Efficient criteria outlined above. If you would like to review your Most Efficient options, contact your Quanex representative for more information. We have tools such as the Quanex Optimizer and technical expertise in insulating glass and PVC extrusions to help meet the Most Efficient criteria, all while giving you the competitive edge.

We’ll continue to keep you posted as we learn more.
Eric Jackson
Director of External Affairs

Download the Quanex Building Products – Most Efficient Recognition Program Finalized