What If We Never Built Another New Building?

Swiss architect Barbara Buser has spent decades proving that the greenest building is often the one already standing. When one unscrews a section of the bright red sheet metal façade from K.118, a former carpentry factory in Winterthur, Switzerland, the interior reveals something few people expect to find inside an award-winning contemporary building. Behind a gypsum fiberboard panel sit tightly compressed straw bales, packed as neatly as if they had come straight from a farmer’s field. Local clay coats the interior walls. The steel staircase once belonged to an office building in Zurich. Massive beams that now support the structure previously carried the roof of a supermarket distribution center in Basel. Eighty windows were salvaged from another building slated for demolition. Most importantly, the project cut embodied carbon emissions by nearly two-thirds compared with conventional construction, according to researchers at the Zurich University of Applied Sciences. In 2021, it received the prestigious Holcim Global Gold Award, one of the world’s highest honors for sustainable construction. For Buser, the problem is that projects like K.118 remain the exception. At 72, the Swiss architect still bicycles through her hometown, Basel, visiting her many projects on two wheels. Belying her unpretentious appearance — dressed in all black, no makeup, her gray hair loosely tied in a ponytail — she has become one of Europe’s most influential architects by refusing to build new construction. Instead, she has saved several of Switzerland’s signature abandoned factories and transformed them into lively neighborhood hubs, all by promoting circular construction: the practice of reusing buildings and their materials rather than demolishing them. For decades, the professional organization of Swiss architects didn’t even accept her as a member because her work is hard to classify, but now her colleagues acknowledge she was just way ahead of their time: She also recently won the 2026 Jane Drew Prize for elevating the profile of women in architecture. Instead of asking what should be built, Buser asks what can be saved. “I’ve reached the point where I say we shouldn’t demolish anything anymore,” she says in her friendly, warm Swiss dialect. “Because of climate change, demolition simply no longer makes sense.” Weighed down by negative news? Our smart, bright newsletters deliver the uplift you’ve been looking for.Or click here to choose exactly which ones you want The construction sector is one of the world’s largest sources of greenhouse-gas emissions and waste, accounting for up to 12 percent of greenhouse gas emissions and over 35 percent of the total waste generated in Europe. The European Commission estimates that more efficient use of materials could cut those emissions by 80 percent. For decades, architects have celebrated the next iconic building, the highest skyline, the shiniest billion-dollar development. But as cities around the world confront housing shortages, rising construction costs and the accelerating climate crisis, Buser’s work suggests that the materials needed to build a more sustainable future may already be here. The greenest building, she argues, may be the one we choose not to tear down. If she were in charge, “I would stop every project,” she says emphatically, “then review them all through the lens of sustainability. If a project cannot meet strict carbon targets, it shouldn’t be built.” Instead of measuring success in Swiss francs, she argues, “the currency should be CO₂.” Buser is much more than an architect. Together with her longtime collaborator Eric Honegger, she has launched more than 20 companies devoted to circular construction, adaptive reuse and community-centered development. They range from her architecture practice to a consultancy for climate-conscious building, a nonprofit urban think tank, a company that refurbishes historic high-end steel kitchens, and organizations that match salvaged building components with new projects. Cooperating with foundations and other partners, she often buys the projects she builds so she can fully implement her vision and keep rents low. Instead of aiming for maximum profit, she plans for “the social value:” “Humankind perishes with this profit system that justifies everything,” she says. “We’re not trying to achieve the highest possible return. We’re trying to achieve the best return for the city.” Rather than beginning with a master plan, Buser allowed future tenants to shape the redevelopment. “We plan together with the people who will use the buildings,” she explains. If a carpenter needs an inexpensive workshop, the space remains rough. If a lawyer requires a representative office, it is finished to a different standard. Instead of forcing tenants to fit a preconceived vision, the buildings evolve around actual needs. Now, children race through a large indoor playground while parents meet in cafés. A theater stages performances in former workshops. Climbers scale a wall in an indoor climbing gym. Physiotherapists, artists, nonprofits and small businesses rent affordable spaces. The rent hovers around 10 percent below market rate because transforming the factory was cheaper than building new. On warm evenings, tango dancers gather in the courtyard beneath strings of lights while teenagers linger beside a small pond. “It was always one of our principles,” she says, “that people should be able to come here without immediately having to buy something.” The same approach rescued Basel’s historic Markthalle. Built in 1929, the domed market hall had fallen into disrepair and faced an uncertain future. For more than a decade, Buser worked to convince investors and philanthropic organizations that preserving the building made more sense than replacing it. Her projects consistently reject the idea that historic preservation means freezing buildings in time. Instead, she transforms them into platforms for new uses. An abandoned bank becomes one of the city’s most popular cafés. A former hospital provides more than 100 apartments. Industrial buildings fill with startup incubators. In Buser’s hands, architecture is less about designing status symbols or squeezing out maximum profit than creating conditions in which communities can flourish. Buser’s perspective has been shaped by 10 years in development work. After graduating in architecture from the renowned ETH Zurich, she spent nearly a decade in Tanzania and South Sudan, building wells, schools and homes with local materials. “In Tanzania there was no such thing as waste,” she recalls. A piece of sheet metal discarded by one person became roofing for another family. Old timber became furniture. Returning to Switzerland in the late 1980s was a profound culture shock. “The overabundance — and above all the wastefulness — really disturbed me.” As a mother and grandmother, “I want my daughter and grandkid to be able to continue to live on this planet and not have to emigrate to the moon.” She traces that conviction back to reading The Limits to Growth, the landmark 1972 report from the Club of Rome. “We live on a planet that isn’t getting any bigger,” she says. “The population keeps growing. We’ve known for 50 years that we cannot continue our wasteful ways and yet we continue as if we had another planet in reserve.” Soon after Buser’s return to Switzerland, a bakery owner commissioned her to remove a commercial kitchen that was only four years old. Rather than send it to landfill, she decided to rescue it. That decision eventually grew into Switzerland’s first-of-its-kind building material exchange. Founded in 1996, the Basel Bauteilbörse has become a marketplace for reusable construction components: windows, doors, structural steel, sinks, kitchens and flooring salvaged before demolition. It now operates in 16 cities. A full-time “material parts hunter,” a young woman, crosses Switzerland and neighboring countries for construction material that fits the current projects. Buser distinguishes sharply between recycling and reuse. Recycling, she says, often means crushing, melting and remanufacturing materials using energy-intensive industrial processes. Reuse preserves far more of the value that already exists. It also requires architects to relinquish total control. Most architects begin with a design and then order the materials required to realize it. Buser reverses the process. Her team first inventories available reclaimed components — windows, steel beams, façade panels — and then designs the building around them. If the available window is slightly larger than planned, her team adjusts the opening. “If you’re looking for a window that’s exactly 1.10 meters by 2.20 meters,” she says with a laugh, “you’ll never find one. But if you say, ‘roughly this size,’ then you can adapt the building.” The method demands more flexibility and, she estimates, about 20 percent more time, but dramatically reduces waste. She argues that complexity should not be confused with impossibility. That shift challenges an industry whose business model frequently depends on demolition, redevelopment and rising land values. Buser believes those incentives have distorted cities. She still lives with her long-time partner in the house her great-grandfather bought, a modest row house in Basel built in 1875 with an idyllic backyard and pond. She was only 18 when her uncle decided to sell the house and the entire row of houses was slated for demolition, yet Buser successfully mounted an effort to keep it in the family and preserve it. The experience motivated her to study architecture, not to construct new things but to learn how to preserve buildings. Her daughter Anne, who swore she would never follow in her mother’s footsteps, first studied social anthropology, but now oversees sustainability at one of the country’s largest construction firms. “That’s like the second rocket stage,” Buser says with a laugh, visibly proud that Anne wants to keep the historic home in the family, too. “I was the first stage of the rocket; the second stage can go much faster.” These days, Buser is attempting to slow down. Nourishing her love of water, she continues to pilot the historic ferry across the Rhine every Tuesday evening, a wooden barge without an engine, just carried by the current. Buser was the first woman in the city’s history to become a licensed ferryperson. The simplicity appeals to her. “Why make something complicated,” she asks, “when nature already provides the solution?” That question captures Barbara Buser’s life’s work. As she moves towards retirement, she has transferred most of her companies into a cooperation. Yet there’s so much to do. She’s currently collecting windows; she has sent over 10,000 to Ukraine to help make houses habitable again. She also founded a foundation that carefully restores the heritage of homeowners without heirs and remodels the homes for low-income residents. And she couldn’t say no when her most ambitious project yet presented itself: the Franck Areal, a 12,000-square-meter former Nestlé food factory on the edge of Basel. Eventually the former factory will include affordable housing built largely with reclaimed materials, workshops, restaurants, artists’ studios, gardens, a dance center, businesses devoted to the circular economy and housing for people with disabilities under unusually secure long-term leases. Walking through the site, as she does in the new documentary Barbara Buser, Pioneer of Sustainability, feels like visiting an enormous materials library. Shelves hold salvaged doors, railings, electrical cabinets and office furniture awaiting their next life. Marble from a former bank lobby has become restroom walls. Temporary fencing is assembled from discarded steel tubing. Concrete ceiling slabs have been cut into stair treads. A lending library rents household equipment, guest mattresses and cargo bikes to residents. Buser laughs when asked whether she collects too much. “I can’t really throw anything away.” For her, every discarded object represents future possibility. Proudly, Buser points to the double-glazed windows in the former Nestlé factory. They were rescued from a demolition project in Bremen, Germany. “What a waste if they had thrown that out!” All scrolling images were taken by Martin Zeller.