Why Cities Want Old Buildings Taken Down Gently

A growing number of US cities are adopting “deconstruction” policies that involve taking structures apart by hand in the name of sustainability.

Emily Christensen knows this sounds a little West Coast, but when she enters the old houses her company has been hired to take apart, she senses an energy. “It’s intense,” she says. “These houses have seen decades of human drama.”

Christensen and her partner, David Greenhill, started their firm, Good Wood, in 2016. Portland, Oregon, where they live, had just become the nation’s first city to require houses of a certain age to be deconstructed rather than demolished. That means that, instead of using an excavator and backhoe to crush an old building, anyone scrapping an older structure in the city must hire a deconstruction crew, which takes it apart delicately—almost surgically—by hand. Rather than a jumble of smashed wood, plaster, fixtures, insulation, concrete, and dust, deconstruction firms can extract cabinetry, masonry, windows, marble, brick, and beautiful old-growth lumber. The idea is that these materials can be sold and eventually reused locally. Christensen thinks of Good Wood, which also remills and sells the reclaimed lumber, as a kind of modern and sustainable forestry company, without the felling trees part.

Deconstruction, as Christensen has found, is a pleasant idea. Using old materials to make new things feels meaningful. It helps, too, that reclaimed wood tends to be very pretty. But a growing number of US cities think the idea makes good policy too. In the past five years, cities as disparate as Baltimore, Cleveland, Boise, and San Jose and Palo Alto in California have adopted their own deconstruction policies; San Antonio has been working on one for four years.

Deconstruction, city officials say, is a green alternative to demolition, sending up to 85 percent less material to landfills. Building materials and construction account for just under 10 percent of the world’s energy-related global carbon emissions, according to the Rocky Mountain Institute. Using salvaged materials eliminates emissions associated with making and transporting new building materials. Plus, it’s not as noisy as knocking down a house, and doesn’t spew dust or toxic materials, such as asbestos, into the air. Backers say it creates jobs even for those without high-tech skills, while highlighting the importance of sustainability. As the climate warms, “the circular economy is one promising alternative,” says Felix Heisel, an architect, assistant professor, and director of the Circular Construction Lab at Cornell University.

Good Wood illustrates Portland’s success. Over the past four years, the city has deconstructed more than 420 single-family and duplex homes that were registered as historic places or built before 1940. Good Wood has taken apart 160 of them. Today, 19 contractors are licensed to deconstruct in the city, thanks in part to a city-sponsored training. The city’s construction waste specialist, Shawn Wood, is one of the country’s leading deconstruction policy experts. He says the cost of deconstruction has gone down since the rule went into effect, though it’s hard to say by exactly how much.

But all that manual labor comes at a cost. Deconstructing a building can be more than 80 percent more expensive than demolishing it, according to a report from Portland State University, though selling some of the recovered material can offset part of the cost.

And sometimes the labor isn’t available. In 2018, Milwaukee required many of the city’s older structures to be deconstructed instead of demolished. But the rule is still on ice, through at least 2023, as officials still struggle to find local contractors who can take apart homes by hand. The delay “is in hopes of building a bigger pool of potential contractors,” says Chris Kraco, supervisor of the condemnation section at the city’s Department of Neighborhood Services. Kraco and his colleagues continue to hold training sessions that the city hopes will help foster a local deconstruction “ecosystem”—companies that can take apart structures; companies that can remove nails, strip paint, and remill the materials; companies that can store or resell the salvaged goods; and companies interested in buying them. Many places also need to update their local building codes to allow contractors to build with salvaged materials.

The complexity has prompted some cities to tackle deconstruction slowly. Pittsburgh just launched a year-long pilot project, in partnership with a local nonprofit construction materials and appliances business, to see whether taking apart old, condemned structures on city land makes financial sense there. In Ithaca, New York, Heisel and his team are helping to deconstruct a 110-year-old home, to test whether the local economy can handle a deconstruction ordinance.

San Antonio’s Office of Historic Preservation, which has spearheaded the city’s deconstruction efforts, plans to propose an ordinance to city council later this year. In the meantime, it’s helping with demonstration projects, including one on a 1930s homestead that uncovered a basement full of moonshine bottles—something that might have otherwise been crushed in a demolition. Researchers suspect the basement was used to store liquor for a nearby speakeasy during Prohibition, says Stephanie Phillips, a senior specialist at the office. The discovery tied in neatly, she says, with the office’s goals of stewardship—environmental, sure, but also cultural. “We’re able to tell a bigger story about the history of development in our city,” she says. “We want to be able to capture that instead of sending it to a landfill forever.”

Most cities, Portland included, have targeted old buildings for deconstruction. It's partly because limiting the pool of homes required to use the technique gives local deconstruction economies time to develop. But also, starting in the 1970s, builders tended to use materials that haven’t held their value, like second- or third-growth lumber, or particle board. Construction also used more glue, spray foam sealant, and other adhesives, which make it harder to take apart new buildings by hand.

At Cornell, Heisel’s lab is looking toward the future. Students and researchers there want to develop building materials that might be easily reused. Guessing how people of the future might want to use a 2- by 6-inch piece of lumber seems difficult. It would also require a better system to track what’s inside a building, for when its end comes. But building with local reuse in mind could completely reorder construction and design. Today’s waste, Heisel says, is only called that “because we are missing the tools right now to understand it as materials.”

Why Cities Want Old Buildings Taken Down Gently