American-Made Challenges


Building Envelope Innovation Prize - Secondary Glazing Systems

This prize encourages production of high-performance, cost-effective secondary glazing systems to improve efficiency of commercial windows.
Informational Webinar #1


The American-Made Building Envelope Innovation Prize will offer up to $2 million to encourage production of high-performance, cost-effective secondary glazing systems to improve efficiency of commercial windows.

Sponsored by the U.S. Department of Energy's Building Technologies Office, the prize targets novel solutions for upgrading inefficient windows to enable building decarbonization retrofits and optimize building envelopes for electrification. The prize will help establish, support, and expand innovation in window systems and catalyze teams to rapidly develop and deploy cost-effective solutions in the secondary glazing systems market. Competitors will secure equity-focused pilot(s) in low-income multifamily or underserved public sector buildings as a component of their commercialization plans.


Approximately 40%* of commercial buildings in the United States have single-pane windows, which result in unnecessary energy usage and uncomfortable occupants. 

Due to high costs and occupant disruption, only about 0.3%** of commercial buildings undergo full window replacements each year. Yet modeling shows high-performance windows could reduce window-related heating and cooling needs by almost 25%, helping the United States achieve a net-zero-carbon economy by 2050.

Cost-effective window solutions must be at the forefront to increase energy efficiency in commercial buildings. Enter secondary glazing systems — window inserts that can be installed without replacing the existing glass or frames or altering the exterior appearance of the building envelope. The primary focus of this prize is to increase adoption of innovative secondary glazing system technologies in the commercial market.

Secondary glazing systems:

  • Can be installed without replacing existing windows or altering the building exterior
  • Can be half the cost of a window replacement—or less
  • Are less disruptive to install as current windows do not need to be removed
  • Increase resilience and comfort
  • Reduce building energy consumption

The American-Made Building Envelope Innovation Prize aims to fund promising secondary glazing system solutions to decarbonize buildings through increased energy efficiency.


Prize Structure

The Building Envelope Innovation Prize offers a total prize pool of up to $2 million across three increasingly competitive phases where each phase concludes with a prize award.

Phase 1: Design Concept

  • In Phase 1, teams provide an innovative concept narrative and design for a secondary glazing system innovation, including details on cost and energy performance.
  • Phase 1 awards will be based on energy and technical performance modeling, cost metrics, and construction plans.
  • Teams can join only during Phase 1, as Phases 2 and 3 will be down-select processes.

Phase 2: Prototype

  • In Phase 2, semifinalist teams must submit a secondary glazing system prototype, technical narrative and secure an equity-focused pilot. 
  • Phase 2 awards will be based on prototype construction, as well as thermal and optical performance tests run by a national laboratory.

Phase 3: Commercialization

  • In Phase 3, finalist teams will work with their equity-focused pilot demonstration partner(s) and submit plans for commercialization. 
  • Phase 3 awards will be based on prototype durability testing results (contingent on prize funding), rigor of commercialization plans, and implementation of equity-focused pilot in low-income multifamily or underserved public sector buildings.

More information can be found in the official rules, on HeroX (the official prize platform), or by emailing 


* U.S. Energy Information Administration (EIA). 2022. Commercial Buildings Energy Consumption Survey (CBECS). "2018 CBECS Survey Data."

** Ciraulo, Rebecca, Valerie Nubbe, Sasha Wedekind, Chelsea Jean-Michel, and Jared Stanley. 2021. Commercial Building Fenestration Market Study. Guidehouse, Inc. Prepared for the National Fenestration Rating Council.



Who is the prize geared towards?

Window and glass manufacturers are encouraged to apply to the prize. 


Who is eligible to compete?

The competition is open only to private entities (for-profits and nonprofits), non-federal government entities such as states, counties, tribes, and municipalities, academic institutions, and individuals. 

For additional eligibility considerations, please review the official rules for the complete application process and instructions for competing.

If you want to receive updates on the prize or have any questions, please subscribe by using the follow feature on the HeroX platform or reach out to




Challenge Updates

Reminder – Public Comment to Phase 2 and 3 Rules Due April 25

April 3, 2024, 6:05 a.m. PDT by NREL Prize Administrator

The April 25 deadline is approaching to give feedback on prototype testing and the pilot requirement for Phases 2 and 3 of the Building Envelope Innovation Prize. Your feedback and input are important to the U.S. Department of Energy. This is your chance to shape the official rules!

As the draft rules stand, in Phase 2 – Prototype:

  • Teams will transform their design concepts into commercially viable prototypes and build a pathway to commercialization
  • Up to three winners will receive $200,000 each in cash prizes
  • Teams will be required to secure an equity-focused pilot partner.

In Phase 3 – Commercialization:

  • First place will receive a $750,000 cash prize and second place will receive a $400,000 cash prize
  • Teams will work with an equity-focused pilot demonstration partner(s) to transform prototypes into commercially viable, technically credible products used in real-world applications.  

The deadline to share your input is April 25, 2024. Please click here to submit your feedback. 

Have more prize-related questions? On May 14, prize administrators will host a second informational webinar, register to join! 

Building Envelope Innovation Prize Informational Webinar Recording and FAQs Posted

March 6, 2024, 9:35 a.m. PST by NREL Prize Administrator

Thank you to those who joined the first informational webinar for the new American-Made Building Envelope Innovation Prize!

On Tuesday, Febr. 27, prize administrators and windows experts from the U.S. Department of Energy and the National Renewable Energy Laboratory presented the goals, requirements, and next steps for the Building Envelope Innovation Prize-Secondary Glazing Systems. View the webinar recording to learn more about the prize and find answers to your critical questions.

A Frequently Asked Questions (FAQs) document is now available on HeroX as well, based on questions from the webinar and general email inquiries. 

Next Steps

  • If you are interested in competing in the prize, please review the Official Prize Rules,
  • If you are interested in supporting an SGS innovation as a building owner or representative, please complete the Prize Interest form,
  • To make your mark on this prize and ensure its success, please share your input on the draft Phase 2 and Phase 3 rules by April 25,
  • Reach out to with any questions.

We look forward to reviewing your Phase 1 submission by June 13, 5 p.m. ET!

Don’t Miss the Building Envelope Innovation Prize Informational Webinar! | February 27 at 11 a.m. – 12 p.m. ET

Feb. 26, 2024, 3:53 p.m. PST by NREL Prize Administrator

Are you ready to join the Building Envelope Innovation Prize? 

Register for the prize informational webinar to get all the details to prepare your Phase 1 entry!  

During the webinar, prize administrators will be on hand to talk about the prize phases, timeline, eligibility, technical requirements, and more. This is your first chance to engage with the prize and get your specific questions answered. To review the all the technical specifics of the prize and the rules for entry, please review the Envelope Prize Official Rules.  

Register now to join Tuesday’s session at 11 a.m. ET. We recommend registering even if you are unable to attend live so that you will automatically receive an email with the session recording. 


ONE WEEK AWAY! Building Envelope Innovation Prize – Secondary Glazing Systems Informational Webinar | February 27 at 11 a.m. – 12 p.m. ET

Feb. 21, 2024, 7:32 a.m. PST by NREL Prize Administrator

Join experts from NREL and the U.S. Department of Energy to learn everything you need to know about competing in the new American-Made Building Envelope Innovation Prize. Experts will share details on the prize phases, timeline, eligibility and technical requirements and reserve plenty of time for your questions. 

Register here for the Building Envelope Innovation Prize Informational Webinar on February 27 at 11 a.m. – 12 p.m. ET.  

If you cannot join the live webinar, a recording will be posted to the HeroX page in the days following. We look forward to seeing you there!