2024's Record Heat: Driving Innovation in Window Technology

The summer of 2024 was the fourth-hottest summer on record for the contiguous United States, with an average temperature of 73.8 degrees Fahrenheit, which is 2.5 degrees above normal. The states of Arizona, California, Florida, Maine, and New Hampshire experienced the warmest summer in their recorded histories this year. Globally, it was the hottest summer since global records started 1880, and the months of June, July, and August 2024 were about 0.2°F (0.1°C) hotter than any other time in NASA's recorded history. These extreme temperatures illuminate the accelerating impact of climate change on our world, and heightens the demand for more temperature resilient, comfortable, and energy-efficient buildings.

Windows and doors, which play a critical role in a building’s energy performance, are coming under increasing scrutiny. According to the U.S. Department of Energy, windows account for approximately 8.6 percent of a building’s surface area and 43 percent of a building’s heat gain or loss. High performance windows can have a dramatic impact on that gain or loss. Additionally, as global temperatures rise, building codes are becoming more stringent. With frequent code changes expected in the future in response to climate change, the window industry must evolve now to meet these new demands.

Thanks to industry advancements and innovations, such as those we are seeing with thin triple and quad glass units, vacuum insulated glass and aerogel glass units, the window industry is starting to prove its ability to meet the growing need for sustainable solutions, reduced energy consumption and improved indoor comfort and air quality. However, it needs to increase the scale of these efforts dramatically to make these advancements and innovations accessible and affordable.

If we fail to act immediately, architects and designers for example, may be forced to reduce window-to-wall ratios to meet energy standards and regulations, compromising the occupants of important natural light and views. The window and door industry could also see market contraction and missed opportunities if it does not push energy efficient, forward-thinking solutions into the mainstream.

The evolution of window efficiency

The journey toward energy-efficient windows began in the mid-20th century with the introduction of double-pane designs. In the 1980s, soft coat low-emissivity (low-E) coatings emerged, followed by gas fills in the 1990s. These advancements were considered game changing at the time. Windows were then added to the Energy Star program in 1998, helping to establish credible baseline efficiency standards. Now, with the October 2023 update to Version 7.0 of Energy Star, windows are being held to more strict performance requirements, reflecting the growing need for industry innovation. In 2023 over a quarter million new homes were certified Energy Star 7.0, but we have a long way to go.

Thin glass technology: Ready today, saving time

Insulated glass units with one or two thin glass center lites offer impressive thermal performance configurations without significantly adding bulk or weight, uniquely enabling existing window designs to reach higher performance levels with costly designs or changes in form or hardware. 

Perhaps most importantly, thin glass units are ready for prime time today – with millions of square feet installed and the lowest “cost per r value” in the market of any emerging glass technology. Extensive efforts by the Department of Energy and Lawrence Berkeley National Laboratory, in conjunction with industry pioneers like Alpen High Performance Products, have worked through various manufacturing, equipment automation and testing hurdles to ensure that technology performs consistently at scale, proving its reliability in real-world applications.

What makes thin glass particularly appealing is that it can often fit into existing window frames and systems. This eliminates the need for costly redesigns and retrofits, effectively buying time for manufacturers, builders, and homeowners as energy codes evolve. With this flexibility, the industry can respond to growing environmental demands without drastically disrupting current processes.

While innovations like vacuum-insulated glazing and aerogel show promise, thin triples and quad-pane units offer a commercially viable, cost-effective option that can be implemented on current window manufacturing lines. To stay competitive, the window industry must balance these cutting-edge solutions with practical applications. Ongoing, research across various technologies is crucial to meet the ever-tightening standards of the future.

As we face unprecedented climate challenges, it’s clear the future of window technology will play a pivotal role in energy efficiency. By embracing a range of solutions—including thin triple and quad-pane windows—the industry can address evolving standards while preserving the benefits of natural light and views. In many respects this is a wonderful time for the fenestration industry to embrace change and rise to the challenge.

This is not just about keeping our buildings cool. It is about securing a sustainable, livable future.