Efficient Windows Collaborative (EWC) members have made a commitment towards manufacturing and promoting energy-efficient windows. EWC is now powered by the National Fenestration Rating Council (NFRC) and we are looking forward to continuing to work with you. NFRC is committed to advancing continuous improvement of windows, doors, and skylights, contributing to making buildings more comfortable and energy-efficient.

NFRC and EWC memberships are now one, stronger membership. We are looking forward to working with everyone to continue to deliver value to our members as well as consumers. Benefits of an NFRC/EWC membership include

Voice and Vote 

Voice and Vote

Training and Education

To learn more about all of the benefits members get, click here.

Please note that the Window Selection Tool is now separate from the membership and is available to anyone in the NFRC Product Certification Program whose products qualify for EnergyStar.

If you are an EWC member, you have two options:

  1. If you are not already, you can become a member of NFRC/EWC – To become a member, click here.
  2. You can simply opt to continue having your products listed in the Window Selection Tool. To continue your Window Selection Tool subscription, please email

If you have any questions about membership, please email Jessica Finn at

About Us

provides unbiased information and education to the public on the energy efficiency, technical, and human considerations that influence window selection and use. The EWC collaborates with allied organizations, educational institutions, and government agencies that promote energy efficiency in residential windows. We do not sell, service, install, or recommend products, or endorse manufacturers. Descriptions and specifications of the products in the Window Selection Tool are provided by the manufacturer. The EWC is not liable for any manufacturing defects or inaccurate product descriptions and specifications and does not guarantee the performance of NFRC-certified windows, doors, and skylights.

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National Fenestration Rating Council
6305 Ivy Lane, Suite 410
Greenbelt, MD 20770
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