Observers of Lake Michigan one day in January of 1935 must have thought they were hallucinating. Not only were the top two levels of a 12-sided house crossing the lake from Chicago to Indiana on a barge, but that house also consisted almost entirely of glass.

The sight of the transparent dodecagon cruising toward a specially built pier would have dazzled anyone standing on the beach in the newly created residential area of Beverly Shores, Indiana, the barge’s destination. Developer Robert Bartlett had purchased this house and four others from the Century of Progress International Exposition for the 1933–34 World’s Fair in Chicago. Bartlett’s brother, Frederick, had started work on Beverly Shores in the Roaring Twenties, and the stock market crash of 1929 hadn’t been great for business. So, after Robert bought out his brother’s share in 1933, he bought five of the fair’s 11 demonstration houses to move there as a marketing stunt. “In the middle of the Depression, he wanted to get people’s attention,” says Judith Collins, historical architect at the Indiana Dunes National Lakeshore.

Bartlett used rolling timbers and a hydraulic jack to get the glass house, known as the House of Tomorrow (shown at top), into place along the lakeshore. He did the same with three of the other Century of Progress houses, which were also brought over on barges: the flamingo-pink Florida Tropical House, the Art Deco Wieboldt-Rostone House, and the prefab steel Armco-Ferro House. (A fifth Century of Progress house, the Cypress Log Cabin, was disassembled and trucked to Beverly Shores, as was the ground level of the House of Tomorrow.)

The houses, now owned by the National Park Service (NPS) as part of the Indiana Dunes National Lakeshore and leased by the preservation nonprofit Indiana Landmarks, still occupy their prime lakeside property. All of them have been restored—except for the House of Tomorrow, a National Treasure of the National Trust. But that, thanks to an innovative partnership between Indiana Landmarks and the park service, is about to change.

On my visit to the Indiana Dunes, angry whitecaps roil the gray-green lake. I’m here on the annual, always-sold-out Indiana Landmarks tour of the Century of Progress houses, and visitors stream in and out of the buildings, undeterred by overcast skies. A tour attendee who grew up going to Beverly Shores in the summers tells me he once peeked into the windows of the Florida Tropical House, unable to restrain his curiosity. “Sixty years later I go in, and it’s still the same,” he says.

Thirty miles across the lake, just before the blocky skyline of downtown Chicago, lie Burnham Park and Northerly Island, the sites of the Century of Progress exposition. The fair jolted people out of their Depression-era doldrums. Attractions such as the Sky Ride (a transporter bridge with rocket-shaped cars), the 200-foot-tall Havoline weather thermometer, and the scandalous fan dancer Sally Rand brought in millions of visitors, and the 1933 fair ended up being so financially successful that the organizers decided to extend it through 1934.

One of the most popular attractions, seen by a total of 1.5 million people, was the Home and Industrial Arts Group, a collection of 11 “homes of the future” sponsored by building product manufacturers and other organizations. The idea was to highlight materials and construction methods that could help make houses cheaper, easier to build, and better suited to modern lifestyles. The Armco-Ferro House, for example, made of prefabricated steel panels with a porcelain enamel coating, was built for the American Rolling Mill Company. The Southern Cypress Manufacturers Association built a log cabin to show the versatility of—you guessed it—cypress.

Other manufacturers highlighted glass block, synthetic wood and stone, reinforced brick, and different types of steel. The state of Florida took the idea even further, building the flamboyant Florida Tropical House to advertise the joys of living in a warmer climate. Newfangled home appliances such as a washing machine and an extra-large mayonnaise mixer were highlighted in a neighboring exhibition hall.

But nothing could top the House of Tomorrow, which featured a built-in hangar containing a propeller plane. A brand-new Pierce Arrow Silver Arrow was parked in its garage. (Cross-promotion was alive and well in 1933.) The house’s floor plan flowed in a circle around a central staircase, rather than the more linear plans most people were, and still are, used to. It contained one of the first dishwashers ever used in a residential application, an innovative “iceless refrigerator,” and an early central air-conditioning system. And the third floor held a glamorous, ocean-liner-like deck that continued all the way around the building. “In planning, in shape, in decoration and in furnishing this is a dwelling which presents a radically different face to the house-minded world,” wrote the Chicago Tribune.

Plus, the House of Tomorrow was almost completely transparent. Visitors to the first World’s Fair, in London in 1851, had been transfixed by the glass-and-iron Crystal Palace. Now here was the first glass house in the United States, available for self-guided tours to anyone who could pay the 10-cent admission fee. One of those tourgoers was rumored to be the architect Philip Johnson, who would go on to complete his own Glass House (now a National Trust Historic Site) in New Canaan, Connecticut, in 1949.

Clearly the House of Tomorrow’s creator, George Frederick “Fred” Keck, wanted to make an impression. Keck was an ambitious young architect from Watertown, Wisconsin, who worked with his brother William in Chicago. He saw the fair as an opportunity to introduce Modernist architecture to the masses, and realized that, rather than working with just one manufacturer, he could get multiple sponsors on board and experiment with a wide range of new materials. Libbey-Owens-Ford, for example, supplied the glass. Goodyear provided rubber floors for some of the rooms, and General Electric contributed the latest appliances.

Keck used an octagonal brick house in his hometown as an inspiration for the building’s unusual form, and the iconoclastic architect Buckminster Fuller’s Dymaxion House (1930) may have influenced him as well. The dodecagon came about for purely practical reasons; that shape simply worked best with Libbey-Owens-Ford’s available sizes of glass panes.

What Keck didn’t realize was that all that glass, exposed directly to the sun, would make the House of Tomorrow very hot. Apocryphal stories abound of the building’s construction workers stripping down to their shirtsleeves in the middle of a Chicago winter. During the fair, the master bedroom had to be closed to the public in the summertime because of soaring interior temperatures.

But Keck learned from his mistakes, and the firm of Keck and Keck went on to design hundreds of quietly groundbreaking passive solar houses, decades before environmental design became fashionable. “Keck was one of the first guys out there saying, ‘We can heat houses with the sun!’” says Chicago architect and writer Stuart Cohen. “He is not adequately credited for how revolutionary he was at the time.”

Today the House of Tomorrow sits on a grassy hillside, sandwiched between the Armco-Ferro House and the Cypress Log Cabin, and across the street from the lakefront Florida Tropical and Wieboldt-Rostone houses. Keck’s 12-sided sensation is currently covered in house wrap and plywood, the better to protect it from the stiff winds coming in off the lake. Rusted metal and peeling paint fill its decrepit interior, but engineering firm WJE has found that the house is structurally stable. It’s part of the Indiana Landmarks tour I’m attending, and most of the visitors seem to see past the decay to the sleek 1930s pad it once was and will be again, after an upcoming rehabilitation. “I’d love to see this when it’s done,” muses one woman as we descend the big spiral staircase from the second floor.

Bartlett sold all five of the houses to individual owners, and they remained in private hands for decades. Federal legislation establishing the Indiana Dunes National Lakeshore, part of the NPS, was signed in 1966. In 1976, the Century of Progress properties were included as a district within the park. NPS purchased the Wieboldt-Rostone House outright, and it acquired the other four residences under its Reservation of Use and Occupancy program, which allowed the owners to remain in the houses for up to 20 years. In exchange, they agreed to sell the properties to NPS at a reduced price. The buildings had never been meant to last beyond the fair, so their construction quality was far from optimal. Their condition deteriorated throughout the 1970s and ’80s, even as they were still occupied.

Then Indiana Landmarks stepped in, concerned about the fate of the Century of Progress houses. “They ended up on [our] 10 Most Endangered List in the 1990s,” explains Todd Zeiger, director of the organization’s Northern Regional office. “The park service didn’t have the cash to restore all five of them.”

By 2005 Indiana Landmarks had leased the entire Century of Progress Architectural District through a partnership with NPS. “The Century of Progress Architectural District represents a large chunk of the cultural resources in the park,” says Indiana Dunes National Lakeshore superintendent Paul Labovitz. “It’s been hard to grow the cultural programs here, because of budget limitations. So partnerships make so much sense. They’re very important in helping us achieve the preservation of built resources in the park.”

Then the real fun began—selecting a group of people willing and able to trade conventional homeownership for the adventure of living in and restoring the houses. They and their families would get to live in a national park, right on (or across the street from) the lake for the next 50 years. Instead of paying rent, they’d shoulder the financial and logistical responsibility for the work themselves, and it would have to be done to the Secretary of the Interior’s Standards—the gold standard for preservation. Finding the right candidates wouldn’t be easy.

But they were out there. Bill Beatty, a mechanical engineer from Munster, Indiana, signed a sublease for the Art Deco–style Florida Tropical House in 1996, using his expertise (and that of his sons, Brian and Jeff, both engineers) to stabilize and replace much of the steel structure. Then, over the next 17 years, they painstakingly restored the original hardware, window frames, aluminum staircase, and other details to their 1934 condition. “The hardware had 60 years of paint on it,” Beatty says. “We sat it in tubs and soaked it in lemon juice for four days to bring back the patina.”

For Gambril; the Lichtenfelds; Bill Beatty and his wife, Lisa Kmak Beatty; and Flint and Jamie Alm (sublessees of the Cypress Log Cabin), life in the Century of Progress Architectural District has its challenges. Privacy is often at a premium, especially during the summer months, when day-tripping Chicagoans and vacationers from all over the country pour into the park.

Lisa recalls how she and Bill once had a group of strangers bring lounge chairs onto their deck and settle in. “Some people are very respectful, and others are not,” she says. “It’s worth it. People here look out for each other.” Ross Gambril concurs. “We’re all friends,” he says. “It takes a different mentality, personality, and work ethic than most people have to even take something like this on.”

The elephant in this one-of-a-kind room, of course, is the House of Tomorrow, which has sat vacant since 1998. And in keeping with its status as the most unusual house at the fair, Indiana Landmarks has decided on a different preservation process for it. “We took the model that we used for the other houses and put it on its head,” Zeiger says. Instead of selecting a long-term lessee to do the preservation work, Indiana Landmarks itself will oversee the work—which still must meet the Secretary of the Interior’s Standards—over the next two years. “We feel we’ll bring the resources to the project and get it done quickly,” he adds.

The $2.5 million rehabilitation will begin this fall, provided Indiana Landmarks can meet its fundraising deadlines. Once it’s complete, the house will be leased for three to five years at a time, giving more people an opportunity to live there. Residents likely will be required to open the House of Tomorrow to the public more frequently than the other houses, to help accommodate pent-up demand.

Glass architecture has come a long way since the time of Keck, and one of its foremost practitioners in modern-day Chicago is Charles Hasbrouck, of bKL Architecture. In 2017 Indiana Landmarks tapped bKL to lead the preservation process. Working with a team of carefully chosen experts, the firm drew up a design that rehabilitates the exterior and the upper two floors. Rather than returning the House of Tomorrow to its 1934 appearance like the other Century of Progress houses, the group decided to use 1933 as its target year, because of cosmetic changes made from 1933 to 1934. “It’s closer to the original design intent,” says Hasbrouck. “The pictures everyone remembers, that were the most widely published, are from 1933.”

The team’s historic preservation architect, Bauer Latoza Studio, has tracked down catalogs and records from 1933 to identify all the building products used in the house. Some of the companies involved—such as Goodyear and General Electric—are still in business, and the hope is that whatever can’t be salvaged can be replicated. Bauer Latoza is also talking to a collector of Vitrolite, the vintage material on the walls in the kitchen, to line up potential replacements. “We’ll be restoring up to 80 percent of the original house,” says Bauer Latoza principal Edward Torrez.

Changes to the first floor—adding a bedroom and an elevator, and transforming the airplane hangar into a functional garage, all within the original footprint—will be made with an eye toward long-term livability. Even more important are the updates to the HVAC system and the glass. bKL will use a combination of a ground-sourced heat pump and variable refrigerant-flow systems to dramatically reduce the energy needed to heat and cool the house without changing its appearance.

And high-tech, triple-pane glass will re-create the House of Tomorrow’s most essential historical feature—its transparency—while preventing the overheating that happened the first time around. “In an all-glass house, if you have glass that doesn’t perform, you have something that’s not livable,” says Ashley Wilson, the National Trust’s Graham Gund Architect, who provided feedback to the design team as part of the Trust’s support of the project. Hasbrouck echoes that sentiment. “To really preserve a house or building in the long term, you have to make it economically viable in some way,” he says. “[This house] has got to be habitable in the summertime so someone can use it.”

The overall result will be a house that looks like it did in 1933 but performs like one built in 2020—true to the spirit of Keck’s futuristic experiment. “It’s even incorporated into the name of the place. In the 1930s, the ‘House of Tomorrow’ had a meaning, and it has one today,” says NPS’ Paul Labovitz. “We’ve learned a lot since then, and we can illustrate that with this building.”