Over the last 50 years, aluminum window walls and curtain walls have become an integral part of modern commercial building design. As ubiquitous now as the high-rises they often encase, these aluminum and glass systems are the standard for tall building glazing. But their impact goes beyond simply design. A building’s glazing impacts how it functions and performs over its lifespan. And that’s where the standard needs an upgrade. 

Fortunately, a fiberglass-framed window wall system is now available. And it’s going to change the world.


The main flaw of traditional aluminum window walls and curtain walls can be summed up in two words; thermal dynamics.

But before delving into thermal efficiencies, a point of clarity around terminology. For the uninitiated, a window wall is one of two types of commercial glazing systems commonly comprising the entirety of a high-rise building’s exterior, with a curtain wall being the other type. Both systems feature glazing that appears vertically continuous from the outside with the building’s structure concealed behind. In these traditional systems, the glazing is commonly supported by an aluminum frame, providing a durable, structurally efficient overall glazing system.

But this structural and economic efficiency comes at a cost to performance efficiencies post-occupancy. The thermal dynamic properties of aluminum window and curtain walls make them amazing thermal conductors. As a general rule, heat passes from an area of greater temperature to lesser, meaning the building is constantly compensating for this heat transfer through the very frame supporting the building’s glazing. That translates to more heat in the winter; more air conditioning in the summer. While a little thermal conduction may seem to be a small problem, the issue is compounded at scale.

Think of a typical 15-story condominium high-rise with window wall glazing—all those linear feet of aluminum, transferring heat. The building’s heating and cooling systems need to be more robust to maintain a comfortable interior temperature. The entire mechanic system takes up more livable space. The operating expense and energy required over the lifespan of the building increases. And considering the substantial costs associated with changing a building’s glazing post-occupancy, building operators are more than likely stuck with those increased operating costs for the duration.

Now imagine an entire city of buildings transferring heat every minute of every day. Imagine the accumulation of those increased costs and energy needs. Suddenly a little thermal conduction becomes a big problem.



Over the last 10 years, jurisdictions across North America have targeted the thermal inefficiency of traditional window and curtain wall systems, introducing building code updates accordingly. For instance, in BC the introduction of the new BC Energy Step Code is starting to effectively limit the amount of glazing that may be used on large commercial and high-rise residential buildings, simply because traditional glazing systems account for so much of a building’s heat loss. Portland, Seattle, New York City, and Toronto have also amended their codes to strengthen—or in some cases increase—the energy efficiency standards of buildings.

Architects and specifiers are finding themselves having to trade natural light, high-rise views and more livable buildings for improved energy efficiency. But it doesn’t have to be that way.



Fiberglass window and curtain walls have long been considering the new frontier of glazing. Mentioned in the same bated breath as a 500-mile electric vehicle and 30% solar panels, the potential impact of fiberglass window walls has left architects and specifiers wondering, when will the day come?

Well it finally has.

Cascadia Windows & Doors has recently launched a complete fiberglass window wall system that boasts 50% to 150% improved thermal performance compared to traditional aluminum systems. With the same structural efficiency and durability of aluminum, Cascadia’s fiberglass window wall is a game changer.

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The company’s patented design is manufacturer Red-List-Free and exceeds many of the most stringent code requirements for thermal efficiency. Available in both double and triple glazing, Cascadia’s window wall delivers R4.1 & R7.1 efficiency, respectively. But performance is only one benefit of Cascadia’s window wall. Perhaps its biggest value-add is the possibilities it opens up.

From increased glazing percentages to reduced HVAC tonnage requirements, from lower operating costs to more comfortable living spaces, the potential benefits of fiberglass window walls are only starting to be understood.

Learn more here.