When it opened in 1933, the Century of Progress International Exposition set out to showcase all things modern and innovative in transportation, industry, and design. Meanwhile, the field of architecture was in the early stages of an upheaval that would change the American landscape forever, with the Modern aesthetic slowly gaining a stateside audience and the likes of Le Corbusier rising to prominence. The fair served as an introduction to modern design for many, and nothing made more of an impression than George Fred Keck's House of Tomorrow.

Then considered a futuristic model home, more than one million people took a tour at the fair. But Keck's house remains noteworthy for the innovations that reached the mainstream not long after. Today, the National Trust and Indiana Landmarks are engaged in a rehabilitation campaign for the building—which was moved to Indiana after the fair—as part of the Trust’s National Treasures program.

Check out the five innovations that have stood the test of time.

Glass Window Walls

In many ways the original “Glass House,” Keck’s House of Tomorrow was a precursor to the glass-heavy Modernist architecture of the mid-20th century. The window walls of the 12-sided, three-story structure represented a sharp departure from the revival styles and bungalows of the time. Predating Philip Johnson’s Glass House by 16 years and Ludwig Mies van der Rohe’s Farnsworth House by 18, the House of Tomorrow’s sleek window walls reflected the kind of optimistic futurism the fair was meant to capture.

Attached Garage

Now ubiquitous around the cul-de-sacs of the American suburb, the attached garage was a rarity at the time of the fair. Even more rare? The airplane hangar Keck figured would soon be a necessity. Well, one for two ain’t bad, and the electric door openers were far ahead of their time—they wouldn’t become commonplace for personal garages until after World War II.

Beyond being architecturally innovative, this vision of a single-family home with a car in the garage would come to drive much of the nation’s development for generations. And who knows? We may yet need those hangars one day.

Dishwasher and "Iceless" Refrigerator

At the time of the fair, the House of Tomorrow’s kitchen was touted as the stuff of dreams. Interior decorator Mabel Schamberg called it “calculated to bring joy and and satisfaction to the housewife.” Originally electric, the home’s “iceless” refrigerator and early General Electric dishwasher were converted to gas power for the fair’s extended 1934 season.

All the way down to the sink and counter, Keck was envisioning a kitchen that made use of the best industrial and scientific advancements, employing a durable and costly nickel-copper alloy called Monel. In the midst of the Depression, the state-of-the-art display was no less than a pipe dream for most, but it was spot-on in predicting the way technology would come to define most American kitchens.

Air Conditioning and Passive Solar Heating

One of the most important design features was the way Keck placed the home’s main utilities in the center of the radial structure, making for efficient use of the home’s innovative central heating and air conditioning system. The House of Tomorrow was actually one of the first houses with air conditioning open to the public. And in the winter, the house didn’t just rely on its gas heat. Keck was an early pioneer in what came to be known as passive solar heating, which he first came to understand when he found laborers working in the House of Tomorrow wearing short-sleeves in February. The deliberately inoperable window walls created a greenhouse effect, and lighting could be controlled by the built-in venetian blinds and curtains.

Unfortunately, the air conditioning system couldn’t keep up, and portions of the home were closed to the public during extremely hot days. But Keck went on to further develop his approach to passive solar heating for residential structures, later incorporating fresh air vents to help control temperature. Over his long career (he died in 1980), Keck designed 300 passive solar houses, most in the Chicago area.

Open Floor Plan

The windows weren't all that made the House of Tomorrow an early example of Modernism. The home’s open, versatile floor plan—borrowing from Le Corbusier and other contemporaries—would also come into vogue over the following decades. In many ways, the entire house was designed from the inside out, starting with the electrical and mechanical systems, then to the floor plan—by which rooms flowed into one another. Interestingly, the inspiration for the shape of the house came not from a Modern influence, but from an octagonal house that Keck knew from his hometown of Watertown, Wisconsin.

But Keck himself made no bones about the fact that the outside aesthetic of the house wasn’t much of a priority. As a promotional brochure explained, "The chief concern of the architect was not to give a specific form to his building, but rather to find a solution to the many and varied new requirements of a residence in a simple and direct manner."