
Growing up in Westchester County, N.Y., architect Katherine Chia never realized how living in a 1940s house designed by architect Edgar Tafel, an apprentice of Frank Lloyd Wright, would play such a significant role in her work today. “That house really taught me about contrast in terms of light and views and the use of windows,” she says.
Chia’s childhood home illustrates one of Wright’s design principles: employing expanses of glass to promote public rooms as primary gathering spaces, where windows framed an outdoor view. Wright preferred calling windows “light screens” and used them to balance natural and manmade environments.

“Connecting indoor and outdoor is a fundamental aspiration for any project because it allows the client to have an emotional connection to the outside, which on a psychological level improves the quality of life for people,” says Chia, a founding principal of New York City-based Desai Chia Architecture.
That aspiration isn’t new. Modernist architects including Wright, Louis Kahn, Ludwig Mies van der Rohe, Le Corbusier, and Luis Barragán integrated windows as portals to frame outdoor views, to direct and control natural light, and to blur indoors and out, concepts that continue to resonate in residential design today.

Form Follows Function
Simplicity, function, and natural light integration were key principles of window design for modernist architects who rejected extraneous ornamentation. As part of his Five Points of Modern Architecture during the 1920s, Corbusier heralded the horizontal “ribbon window,” a term he coined. His concept—to see windows as picture frames and as key to a building’s design aesthetic—differed from pragmatists, such as Austrian architect Adlof Loos, who “just punched windows as simple as possible,” says Austin architect Scott Specht, founding partner of Austin, Texas-based Specht Novak.
Corbusier “insisted on ribbon windows and long strips of glass,” Specht says. “Over time, that evolved into full walls of glass. It’s become one of the biggest indicative features of a modern house—to have giant areas of glass and the merging of the interior and exterior.”

While humans began making glass more than 4,500 years ago, it wasn’t until the end of the 19th century that modern forms of glass became reliable and accessible, says Andrew Heid, the founding principal of New York City-based NO ARCHITECTURE and author of the introductory essay for Glass Houses (Phaidon, 2023). Only then did architects integrate the material with other innovations of the time, combining it with the skeletal structure.
“Mies was the one who wanted to turn everything into an aesthetic object,” Heid says. “He was interested in the poetic qualities of a modern diagram. Unlike the other great masters of the modern movement, Mies understood [glass] on a spiritual level. He understood it as a kind of organic form, a crystalline form, an industrial form. This idea of nature was already embedded from his earliest sketches.”

Transparent Connections
Like Chia, Heid, who grew up in Oregon, was also influenced at an early age by Wright’s use of transparency to celebrate nature. “Transparency is one of the most powerful ways to frame nature—to remind ourselves that we’re connected, we’re part of nature, we’re part of a larger whole,” he says.
Van der Rohe’s Farnsworth House, completed in 1951 outside of Chicago, is a prime example of transparency, Heid says. Sitting more than 5 feet above ground, the home’s glass pavilion has views of nature encompassed by floor-to-ceiling windows, embodying the architect’s idea of “a functional relationship between a house and the surrounding nature.”

“We are so disconnected from nature today, and yet we need nature more than ever,” Heid says.
One of his designs, the Flower House in Massachusetts, reinterprets the concept of the glass house with the natural landscape literally pulling up around the outside and inside of the structure. The house features six interlocking timber canopies above an open central courtyard with views of nature in every direction. “One of the byproducts of glass is the way the light moves through the dwelling,” he says. “Natural light is perhaps the most important thing, besides working with gravity, an architect can use.”

Light Control
While the Farnsworth House and other mid-century glass houses by Lina Bo Bardi in São Paulo, Brazil, and Philip Johnson in New Canaan, Conn., take in a wide view of nature, other modernists—and practicing architects—use windows “almost like an Alice in Wonderland lens to a different world,” Chia says. “Sometimes it’s that small window that is the counterpoint to the big moment that is the surprise. To have something curated and sculpted helps people reset.”
Louis Kahn used windows, Chia says, “to allow the light to come in and sculpt the space and create iconic moments of architectural framing.” Kahn designed the library for Phillips Exeter Academy in New Hampshire in 1968 as a light-filled spiritual sanctuary, for example. Book stacks were organized toward the interior, while individual reading carrels lined the double-height, window-walled perimeter, thereby protecting the books from rays of light.

Kahn’s use of windows and skylights at Exeter—and in his other designs—allowed natural light to interact with the structural materials. “When the light comes in, it’s hitting concrete or teak and it’s activating all of these beautiful materials,” Chia says. “It’s all about what’s at the window and what moves away from the window, what benefits from the light and what should be protected from the light. It’s using windows as a conceptual theme.
“He’s one modernist who I think really tried to think about light and the way it shifts across the day and across the season, to think about how light can activate materials at times, then as it recedes and the material kind of goes quiet,” Chia says. “You’re constantly renewed in terms of the experiences with the materials.”

Interior Glass
On the flip side of glass house curtain walls are structures that play down exterior views yet channel light and capture nature through interior panes of glass. Barragán, known for his vibrantly colored stucco walls and water features, was one of the modernists to celebrate interior courtyards. His designs captured light and shadows and dissolved visual boundaries with window walls that overlooked gardens. His own residence in Mexico City, completed in 1948, features glass walls with views of a garden. Later, also in Mexico City, he designed Casa Gilardi around a single jacaranda tree.
“In a beautiful garden, the majesty of nature is ever present, but nature reduced to human proportions and thus transformed into the most efficient haven against the aggressiveness of contemporary life,” Barragan wrote in his acceptance speech for the Pritzker Architecture Prize in 1980.

More recently, when Specht designed his own RADA-winning home in downtown Austin, the architect eschewed exterior windows, and yet “there’s more light here than I’ve ever lived with in my life,” he says.
The 1,100-square-foot floor plan features floor-to-ceiling glass walls that frame two interior courtyards, one that features an olive tree and the other, an aviary. “The outdoor space becomes part of the living space, even if you never walk out there,” Specht says. He adds that turning the window focus to the interior of the house is especially conducive to living in an urban setting. “I drive through Austin, and I see a modern house that has a full glass front on it facing the street, then there’s inevitably a fence that’s been thrown up in front of it that kind of destroys the entire idea.”

Future Prospects
As technology evolves, so do the ways in which contemporary architects innovate using glass and windows beyond what the modernists could have conceived during their time. Larger panes of glass, thinner mullions and glass profiles, UV protective coatings, and triple-glazing are already game changers.
Heid imagines a day soon when glass, which is already much stronger, thinner, lighter, and less expensive, uses less energy to make. “We may not even have to make opaque walls anymore,” he says. As much as the architect who wrote the introductory essay for a 237-page book about glass houses is interested in the topic, he’s quick to point out that he’s not an expert on the material. “I’m interested in glass for really one property, which is for it to disappear.”