Groundscraper City: Touring the Subterranean Structures of Minneapolis-St. Paul 1978–1983

On a typically chilly Upper Midwestern afternoon on April 5, 1980, after a day of seminars and presentations, a group of about twenty architects, engineers, geologists, urban planners, and policy experts, all clad in winter jackets, piled into a charter bus outside the old Leamington Hotel in downtown Minneapolis. They were headed out on a two-part tour of four notable underground structures in the Twin Cities, all of them constructed within the past five years.

Early April is still winter in Minnesota. The bus was unheated, but the interiors of the four buildings were considerably more comfortable. As the deeper earth surrounding them maintained a subterranean temperature of 50 degrees year round, each structure required only minimal heating to reach room temperature. “Energy savings of up to 75% are possible in underground space,” the conference literature cheerfully reminded the attendees.

These four buildings represented a new wave of progressive architecture making its home in the region. The Upper Midwest was a perfect test site—both geologically and politically—for trying out big ideas about how underground architecture could reflect a new type of environmentally conscious post-oil society. The state legislature, under the guidance of a bipartisan commission on natural resources, had kicked off a boom in underground structure construction in the state with a number of funding recommendations for study of the topic, and later, a handful of building projects. This included a dedicated Underground Space Center at the University of Minnesota, who were co-sponsoring the event. The attendees were there to see what these structures looked like up close, to poke and pry and ask questions.

Most on the bus were already involved with the underground space movement, but in-person visits were an important tool for introducing underground buildings into the mainstream of American architecture. The director of the Underground Space Center, Ray Sterling, wrote that year that “such firsthand inspections often serve as a major turning point in people’s perceptions and assessments of earth sheltered housing.” The hope is that the conference-goers would return home and take with them the lessons that Minnesota engineers, architects and planners had learned the hard way. If it could work in Minneapolis, maybe, it could work anywhere.

If you’re a person who finds yourself interested in utopian architectural plans of the Whole Earth Catalog era, there are vast sections of the design-focused internet devoted to intriguing scrapped ideas, gauzy proof-of-concept illustrations, and faded snapshots of lone geodesic domes out in the high desert. Unlike so many of those plans, however, progressive architectural and engineering ideas originating in Minnesota in the 1970s and ’80s exist outside gouache painting renderings and out in the world, on a fairly large scale. These underground buildings still exist. Together, they represent an ecological and architectural legacy that is, by design, hidden from view.

For the most part, it’s possible to recreate the 1980 tour of earth-sheltered structures in the Twin Cities almost four decades later. At least six noteworthy earth-sheltered structures from this era remain in the twin cities of Minneapolis and St. Paul and their immediate first-ring suburbs; of the three that don’t, two were demolished in the 2010s, and one collapsed in the 1980s.

Retracing this tour today provides some insights into how an earlier generation, galvanized by the energy crises of the 1970s and a distant but quickly approaching sense of ecological disaster, hoped to address energy and environmental issues that have still not been resolved in the four decades since. “During the late twentieth century it became evident that human activity has the capacity to alter the natural history of the world, destabilizing the global climate and poisoning the natural environment,” wrote Minnesota architect David J. Bennett in those years. “Some new directions have to be tried.” In the 1970s and ’80s in Minnesota, that direction was down.

Williamson Hall, on the East Bank of the University of Minnesota, is the first stop. When it opened in 1977, the awards had been piling on for a few years: before it even opened, the design won a special commendation from Progressive Architecture in New York. It later received special commendations from regional landscape architecture organizations.

The building was constructed as a facility for the office of admissions and records, the campus bookstore, and the Minnesota Book Center. It’s a diagonal, angular structure, bold in appearance but also quite reticent, peeking up through the ground in parts, but ceding the spotlight to the old stone piles that surround it.

The bookstore is now gone and with it, public access to the open, light-filled atrium that was meant to provide social space for thousands of students. The building today still houses the office of admissions, along with the offices for the physics and astronomy department. The underground configuration solved a number of problems for the university in the mid-1970s. For one, it preserved the sightlines in an important stretch of the campus’ most historic section, creating thousands of square feet of usable space without cluttering up an already crowded part of campus.

More importantly, though, it served as a showcase for how the university could rise to meet the challenges of the era, and conserve energy at a time when fossil fuel seemed to be running out. Not only was it earth-sheltered for maximum energy efficiency, but with support from the Department of Energy, it was arrayed with a system of solar collectors not dissimilar from those President Carter had installed on the roof of the White House. Those would, unfortunately, be made obsolete as photovoltaic technology improved over the next few years. By the mid-1980s, oil prices had dropped again, and most Americans forgot there had ever been an energy crisis. From the perspective of the early part of the decade, it began to look a little like a relic of a bizarre, pre-”Morning in America” era of heedless countercultural experimentation. Students called it “Lake Williamson,” as the windows in the atrium frequently leaked, pooling water on the floors.

Williamson remains, though, looking more or less as it did in 1977. Its lead architect David J. Bennett, speaking with the soft Brooklyn accent of his childhood in Manhattan Beach, complains today that it was “butchered,” but remains proud of the building. Bennett’s website, a vast compendium of images and text relating to his work and architectural practice, highlights it prominently. Of all of these underground structures, it’s the most easily accessible today—you can just walk in during regular campus hours. When you enter the elevator on the lower concourse, you find a pleasingly counter-intuitive, upside-down format for the buttons: B is at the top, going down to 1, 2 and then 3. A walk through the concourse leads out onto the sunken courtyard, surrounded by concrete and a lush layer of plants, and giving you an opportunity to crane your neck upwards slightly for a brochure-ready view of the ring of historic buildings looming over you.

It feels a little like standing in an excavation for a future that never quite happened. The poured concrete forms, forty years later, call to mind not historical structures, but instead the dystopian science fiction of that period. It’s the hard-edged, modernist vistas of A Clockwork Orange or Truffaut’s adaptation of Fahrenheit 451, which of course made heavy use of the existing brutalist architecture of postwar London.

It’s a little funny and a little gloomy that the only context we have for experiencing these types of structures today is science fiction. Walking through the concourse out into the courtyard, it calls to mind what some writers like Mark Fisher have dubbed “hauntology”—an uneasy nostalgia for lost futures, a new society promised and hinted at in those idealistic years, but never fully achieved.

Underground architecture was, in this context, not connected to utopian (or, if you prefer, dystopian) ideals tumbling down from a distant centralized planning committee about how the future should be. It was, instead, built into the earth of the Midwest as a regional movement. Bennett recalls that what fascinated him was integrating buildings into the landscape of Minnesota. “It irritated me that the attitude of landscaping was decorative,” he said. “The earth was just a platform, and everyone celebrated the objects and forgot the relationship with platform was somewhat tenuous.” To this end, Bennett worked with the university landscape architect Clinton Hewitt to create a system of containers containing a species of native deciduous vine plant. In the summertime, the vines grew rapidly, shading the interior space. In the winter, it retreated, allowing light to stream in and warm the common spaces. “The whole idea,” he explains, “was to make an integrated system.”

Bennett had moved to the Midwest from his native New York, in part because of the lure of the Prairie School. “What was unique about the Prairie School,” he says, “is that the architects looked at the land, and the geometry and geology, and said what we need to do is develop buildings that express the land—the horizontality. It’s a uniquely Middle Western concept.”

He pauses and smiles wryly. “I learned something that only naïve young people learn—culture is a function not only of place, but also of time. The Prairie School was done. All I’d hoped to find were not there.” What he found instead was a community of like-minded architects and planners, including fellow East Coast transplant and dean of the architecture school Ralph Rapson—even if the Midwesterners he worked with found his Brooklyn-bred forthrightness and aggressiveness as a young man perplexing. “I had not anticipated it, but I suddenly found myself in a very supportive, collaborative environment. In New York, you had to fight like hell to do something that wasn’t a penis. All the students wanted to do the next Chrysler Building.”

At the time, Bennett wrote about the work in an expressly Midwestern way, with innovations like underground architecture following in the tradition of the Chicago and St. Louis architects of the previous century. In a 1983 issue of Architecture Minnesota, Bennett asserted that “we are equipped to deal with our unique climate in a unique way,” and that “what is required of us is to shake off our timidity, re-assert our self-confidence and instead of purchasing an ersatz culture from elsewhere, risk creating one of our own.”

The next stop is the Seward Townhomes, on the other side of Interstate 94, at the corner of 9th Street and 24th Avenue. As in many large metropolitan areas, the promise of the interstates in the 1950s and ’60s was to connect automotive commuters to the centers of population quickly and efficiently. Even as late as the 1970s, the interstates still had a vaguely futuristic, technologically sophisticated sheen to them—Minneapolis’ favorite son Prince’s first synth-funk band was called 94 West. They did connect the two downtowns, but they also resulted in the mass displacement of established neighborhoods—particularly neighborhoods of color—and brought with them noise, pollution, and a shredded urban fabric.

In 1979, Mary Tingerthal was a recent college graduate working as manager of home improvement programs for the Minnesota Housing Authority. In addition to her regular work with the agency, she’d also volunteered to help administer a Minnesota legislature-funded demonstration program on earth-sheltered housing, managing a number of design contests for structures around the state, mainly just out of the urban core. Work around earth-sheltered structures became a large part of her job.

She was on this 1980 tour, as well—one of many across the US she attended through the late 1970s and early 1980s. “It was a brief but intense phenomenon,” she recalls cheerfully. “They trotted us around between conferences all over—Colorado, New England. I’d talk to people about considerations when they were getting mortgages. I never expected to be involved with this, and never more than as an interesting thing I’d do at work.”

But the connection became quite personal for Tingerthal when she moved into one of the Seward Townhomes: “I was so swept up! I wanted my own earth-sheltered housing.” Since it was for sale in the open market, there were no conflicts of interest, and so she bought one of the units. She lived there for nearly a decade, first one her own, and then with her husband, ultimately selling it to a nurse at the nearby university hospital.

The Townhomes were meant to be a showpiece for earth-sheltered architecture, and to correct some of the damage the interstate had done to the urban fabric. The townhomes face I-94 and are, by all accounts, exceptionally quiet considering the amount of traffic just feet away. The reason why the site was developed in the way it was, with such a willingness to try out new ideas, is that no one else wanted to develop a site so close to the freeway. They’d rendered the site almost unusable.

Walking the sidewalk in front of the Seward Townhome today, you’re confronted with that distinctly ’70s-era mixture of hard-edged concrete and billowing greenery spilling out of planters. The entrances are set back into the earth, appearing almost as if on the side of a hill. One of the reasons why underground architecture took hold in the imagination of the Upper Midwest of the time is that it drew heavily on popular narratives about and self-perceptions of the region: the Underground Space Center at the University of Minnesota was funded in part after an late 1970s trip to Sweden to visit underground structures there, and an enthusiastic group of returning academics and Minnesota legislators drew direct connections, as so often happens in the Upper Midwest, between the culture and geology of Scandinavia and Minnesota. Early writing about underground structures in Minnesota took lengths to point out that it was nothing new in the region—the sod houses of prairie homesteaders and pioneers in particular were invoked early and often, guarantors that this new way of thinking wasn’t too out there, but rooted in centuries-old Midwestern traditions.

It’s true, though, that underground architecture is uniquely suited to the landscape of Minnesota, both above and below ground, where the unique geology of the region layers soft sandstone and hard limestone in a way conducive to subterranean construction. Public-private partnerships such as the townhomes were meant to show that such buildings could fit into the landscape, and create modern, energy-efficient structures that were suited for the climate, as well. Heating and cooling an aboveground house requires accommodations for an external temperate that can swing between a hundred degrees and negative thirty degrees. An underground structure, however, surrounded by fifty-degree earth at depths of twenty feet or more, needs only to be heated by twenty degrees to room temperature, and doesn’t need to be cooled at all, once solar energy is taken into consideration. In the period of time between the 1973 oil embargo and the 1979 energy crisis, such a model looked very attractive, even viewed strictly from an economic perspective.

The roof of the Seward Townhomes no longer has visible earth-berms, as it did in 1980, when the conference attendees walked through it. The residents, in response to leakage problems, sued the contractor and had a conventional roof built over the sterilized earth cover—if moisture problems aren’t addressed early in the process, or your builder cuts any corners, it’s much harder to make repairs later. In this case, repairs put an end to the moisture problems.

“It absolutely worked,” Mary says of her home. “It was really quite quiet. And my energy bills in January were astoundingly low. I learned a lot about concepts of energy conservation, about taking advantage of passive solar. That’s a part of the lasting legacy—how passive solar can fit into a design. It’s a natural marriage.”

These units are some of the quietest structures in this noisy part of the city. They’re private homes, but if you have a chance to step inside one of the units sometime, do it. The way the light streams down at an almost 45 degree angle through the south-facing windows in the afternoon, and the stillness that surrounds you, is quite sublime. It is a little like stepping into a machine engineered to keep its occupants concealed within a perfectly balanced and nearly monastic state of light, warmth, and silence.

The third stop, at 474 Concordia Avenue, is an unremarkable-looking brick box housing the Minnesota Safety Council. The building that once lie below this site was known as the Criteria-Control Data Corporation Building, or the Terratech Center. Control Data Corporation (CDC) was a leading supercomputer manufacturing firm in the 1970s and ’80s, and when the Terratech Center opened in 1981, it was hailed in the pages of the New York Times as “the most ambitious of the nation’s corporate groundscrapers.”

Nineteen eighty-five was not a great year for underground spaces. “The decade of business and finance,” sighs Ray Sterling. “Everybody sort of forgot about worrying about energy—there seemed to be money and energy, and the whole second half of the decade went towards how to maximize your profits and financial status than the environment and energy.” Bennett echoes this thought: “All the greedy people wanted to buy as much as they could, burn as much as they could, and go home with their loot.” Energy-related funding for the Underground Space Center had dried up by the mid 1980s, and the center shifted its focus to other equally important though less visible applications –management of underground utilities, for example.

It remains unclear what happened to the underground building at 474 Concordia, but after a particularly heavy rain, the steel culvert structure in the building’s north-facing wall collapsed, a 49-year-old CDC librarian named Maxine Ann Murray was killed in her sleep. Murray was sleeping on a couch outside the apartment she also lived in; the building incorporated some living space along with the office space and a fruit and vegetable garden in a greenhouse. The architect, Jerry Allen, was interviewed in the paper the following day. He was quoted as saying he had no idea what had happened.

When the site was redeveloped a few years later, the current aboveground design was chosen, and the space in the earth was filled in. Two other underground structures built in the late 1970s in the Twin Cities met less traumatic but no less conclusive fates: the underground Walker Library in Uptown Minneapolis closed in 2014 for two years of renovations, and the visitor center at Fort Snelling historic site a few years later. Both were built to preserve sightlines, conserve energy and—maybe just a touch here—to show off a little by big clients eager to get in a on a hot trend, even if it didn’t make a lot of sense for the sites.

“It had no neighborhood presence,” said Jennifer Yoos, an architect working on the redesign of the library, which opened atop the site of the old earth-sheltered building in 2016. “People didn’t know it was there.”

The visitor center at Fort Snelling, though it succeeded in preserving the sightlines along the bluff it was built into, apparently had moisture issues from the beginning. The writer of a 2007 report on the facility threw their hands up in something approaching disgust when addressing the core issues: “There is no clear evidence whether the ongoing water infiltration is due to static pressure in the bluff, the location of the building on an underground spring, the fact that the building roof is the lowest point on the site, or more likely a combination of issues.” As of the beginning of 2019, the old center is scheduled to be shuttered and abandoned in favor of a repurposed cavalry barracks elsewhere on the site.

The final building on our trip, the Girl Scouts Building at 400 South Robert Street in St. Paul, is an example of how some of these structures have survived, and are hiding in plain sight. The building has been renovated twice since it was constructed in 1979—an expansion in 2001 that surrounded much of the original earth-sheltered features, and a total remodel in 2017 that added several thousand square feet, but further obscured what remained of the original design. Unless you note the earth-sheltered windows on the south side of the building, which offer a glimpse into a subterranean concourse, you’d never realize it was anything other than a standard administrative building on a commercial strip of St. Paul.

The vision of the late Girl Scout Council of St. Croix Valley Executive Director Thea Childs drove the fundraising and then construction of the building, then known as In Town Center. Coming not from academia but from the nonprofit sector, Childs was an idealist and passionate environmentalist who wanted a site that could serve as model to both other organizations, and to the girls her organization served. It was, she said, “a teaching tool,” complete with color-coordinated pipes that could be used to educate girls on alternative energy and conservation. A waterless, Scandinavian-designed composting toilet called the Clivus Multrum was installed, after a period of initial resistance from the plumbers union, who had lingering professional concerns about installing a waterless toilet. Featuring a green roof with solar and wind power features, the centerpiece of the building was a two-story earth-sheltered atrium that served as a living library of plant life. In the original design, you entered the building through the atrium, into an airy, light-filled and humid greenhouse oriented around a water feature and fountain. The atrium was also home, apparently, to a number of pink flamingos, who made their home among tropical fishes and prairie grass.

The flamingos, fountain and Clivus Multrum are all gone now, along with many of the original features. The bravura bank of windows lighting and heating the atrium is today a suite of cubicles in the rear of the building, but it still retains the sleek, angular glass and blonde wood contours that suggest its 1970s roots. Over time, the solar and wind features atrophied and were removed, piecemeal, from the structure. One of the few remaining elements of the original design is tucked away in the boiler room: the pipes still retain their bright blue, green and red color-coding. The pipes that run over the atrium, however, have been repainted a flat gray.

In some respects, a tour of this kind is not a great format for appreciating these types of buildings. As helpful as it is to see each building in its environment, singling out specific structures also privileges the uniqueness of each site, as opposed to how they might work as part of a larger system. Underground buildings work best when they’re part of a system, suited for the site and working in concert with the surrounding urban and natural environments. And of course, it doesn’t work everywhere, even in landscapes best suited for them.

“We might promote the consideration of underground space use,” Ray Sterling says of the work of the Underground Space Center, “but we were not in the business of promoting it for building without regard to whether it made sense or not. I think you’ll find some of the examples around Minnesota in that mix—some which were fairly successful or appropriate for the site, and some which were . . .” He pauses. “Well, people just liked the idea, and shoehorned it into a site.”

That stigma of trendiness can be difficult to shake as time goes by. “It’s a challenge to get that balance,” Sterling tells me. “Where I think they really make the most sense is where the ecological and environmental aspects work with the energy aspects and the site to form a natural success. Because if you’re only interested in an energy-efficient building, it’s reasonably true that you can heavily insulate it and put in solar, and you can get a building that uses a very small amount of energy, and you can do that without building underground. But when you take a site where you want to preserve the characteristics of the site, or not intrude on the natural environment, and you want a good energy performance to fit with the landscape, then using the underground space and putting all or part of the building underground starts to have more success factors associated with it.”

The mechanics of earth-sheltered buildings aside, the emphasis on energy performance during the period has had a long and lasting effect on architecture. Solar power and earth-sheltering went hand-in-hand, and even when the latter fell by the wayside, the innovations in solar energy specifically and energy efficiency developed alongside earth-sheltering remained, and gradually entered the mainstream conversation after decades. Minnesota adopted some of the earliest energy efficiency standards for new buildings, and many of those standards came out of the work pioneered at the time.

“It raised awareness of the impact of design and siting of residential buildings on energy performance,” says Tingerthal. “In terms of green building standard, I think it got a practical start then. We financed thousands of affordable units of residential housing, and they were all required to be built in accordance with those standards. It’s now a part of what we do.”

Near Williamson Hall, built three years after the 1980 conference, stands the Civil Engineering Building, also designed by Bennett and also an award-winner, edging out the Epcot Center for 1983’s Outstanding Achievement Award from the American Society of Civil Engineers. It’s a truly remarkable building, an inverted high-rise plunging seven stories in the earth. When it’s written about, what’s most frequently highlighted are its most fantastical features—a passive lighting system that would spread light into the bottom stories, though now inert through an evident lack of interest in maintenance from the university, as well as a device called the Ektascope, meant to provide a 3D view of the outside courtyard optically reflected in a screen on the bottom floor, and intended to mitigate the psychological discomfort that comes with being below ground. Today, it’s a black mirror.

But fantastical as those features are, they’re not the primary draw of the building. Despite some ongoing challenges with moisture and leakage, the building remains one of the most energy-efficient on campus. Standing on the bottom floor, seven stories below the limestone cap, in an artificially lighted hallway looking at an elevator bank where the numbers runs backwards, there’s a quiet, odd feeling of being displaced from a future that didn’t turn out as radically optimistic as planned for the Upper Midwest.

Perhaps it didn’t. However, there’s also a parallel feeling that, decades removed from the specific political and ecological discussions of the period, nonetheless still registers as powerfully, viscerally Midwestern. These are buildings created to harness the most basic characteristics of the surrounding landscape and the larger environment. Those lessons remain.