The next chapter in fiberglass performance is here. Built on more than six decades of innovation, MILGARD C700 Fiberglass Series windows and doors deliver lasting strength, refined design, and exceptional energy performance — engineered for the homes of tomorrow.
Why fiberglass: the strength behind the design
Fiberglass is one of the most durable, energy-efficient materials for windows and doors today. The material’s strength supports larger glass panels — ideal for wide-open views and modern designs.
“Homeowners, and therefore our customers, are desiring larger units all the time,” says Troy Kunkel, MILGARD’S Engineering Manager for New Product Development, “so that was a big focus for us when designing C700.”
Another advantage of fiberglass windows is that they expand and contract at nearly the same rate as glass, reducing the stress on seals.
At the same time, the low rates of expansion and contraction make fiberglass windows a superb choice for regions that experience extreme temperatures.
“C700 is going to perform very well in hot climates, and it’s going to perform very well in cold climates,” says Kevin Anez, MILGARD’s Vice President of Engineering and Product Development. “It’s a very strong, stiff, and rigid material.”
Performance redefined: Built stronger, built smarter
When tasked with developing a modern window design, MILGARD engineers knew that they had a solid head start with C650, MILGARD’s current fiberglass offering that has been on the market since the 1990s. Their goal: build on the proven C650 and deliver even greater performance.
“We’re looking for better and better thermal performance all the time,” Kunkel says. “Through our different design methodologies, we achieved up to a 10 percent improvement in our thermal performance from the C650 line.”
“Our industry gets pushed to have a higher structural performance, bigger products, and better thermal performance,” Anez says. “Our customers consistently want all three of those things, and I think we delivered with C700.”
The team also focused on enhancing acoustic performance.
“Another feature of C700 is that the glazing pocket accommodates multiple thicknesses of insulated glass units, which allow for a variety of acoustical glass packages.”
Where modern design meets timeless style: the superior aesthetics of C700
In addition to durability and performance, the MILGARD design team knew that they had to prioritize aesthetics on the new C700 windows. They set out to create a modern design with clean lines and a range of aesthetic options.
The result is a window with timeless appeal hat complements any architectural style.
“The ask from our customers was for a fiberglass product that had a more contemporary style,” says Erik Ashcraft, MILGARD’s Product Manager. “C700 is a very contemporary design with very simple lines that won’t go out of style.”
MILGARD C700 windows and patio doors come with a variety of aesthetic options. They’re available in six colors – white, black, bark, bronze, adobe, and steel gray – and the hardware is available in those matching colors in addition to satin nickel and oil-rubbed bronze.
Proven legacy, trusted insights: C700 is a continuation of the MILGARD Tradition
For decades, MILGARD has led innovation in the fenestration industry — a legacy the team takes great pride in. And that innovative expertise can be seen on C700, particularly in the use of automated manufacturing equipment that helps create a consistent product.
“We’ve introduced automation wherever possible,” Ashcraft says. “It allows us to build the window the same way every single time with the consistent quality our customers expect.”
Another design challenge on C700 was the development of a superior corner joinery system to ensure protection against water and air infiltration. Here again, the MILGARD design team used its ingenuity to solve the problem.
“The corner joinery in particular is something that I’m very proud of,” Ashcraft says. “It’s a unique corner key system that has fastener ports as well as sealant ports. As part of the automated process, the lineals flow through the production line, are automatically squared, fastened mechanically, and then sealed.”
Designing for tomorrow: the future of fiberglass windows and doors
MILGARD C700 windows and patio doors combine advanced engineering with timeless design — built for today and ready for what’s next. Contact your MILGARD representative or visit our website to learn more.
