Devon Henry, CEO and president of Team Henry Enterprises in Richmond, Virginia, is known for building things. Clients of his award-winning general contracting firm include the US Army Corps of Engineers, the Department of the Interior, Dominion Energy, and Bon Secours Health System. His federal contracts alone account for $100 million of work, according to a report in the New York Times.
But in 2020, the State of Virginia and the City of Richmond asked him to instead deconstruct something. They needed someone to dismantle the infamous Confederate statues there, remnants of the Civil War. In the wake of civil unrest, the protests that followed George Floyd’s murder that summer, both the governor and the mayor determined it was time to remove these painful bronze paeans to those who once defended slavery.
As an African American, Henry accepted the task of dismantling the Monument Avenue sculptures with apprehension. As he anticipated, the work came with racist and dangerous threats to him, his company, and even his family.
But his team persevered and has since removed 23 such monuments in the South, including the infamous Robert E. Lee statue in Charlottesville, the center of deadly neo-Nazi protests in 2017.
Not all demolitions come freighted with such animus. But how and why we need to demolish existing structures—and the environmental and financial costs of doing so—illustrate the controversies that come with the end-stages of the built environment.
Fortunately, those same controversies drive innovation and solutions.
Some demolitions are necessary when a building is unfit for occupation and financially unviable. Sometimes, still-functioning buildings are sacrificed because the land on which they sit is more valuable for other purposes, typically larger structures.
But the cradle-to-grave nature of most building demolitions is often environmentally problematic. The US Environmental Protection Agency estimates that 600 million tons of construction and demolition debris is generated annually; this is twice the size of general municipal waste. Recycling of demolition debris does happen—up to 65 percent of concrete is reused in Palo Alto, California, for example—but there are barriers to 100 percent material reuse. They include asbestos contamination as well as mixed materials (wood, plaster, metals, plastics) that are hard to separate. Further, transportation of demolition debris has its own carbon cost, regardless of whether it goes to a landfill or a recycling facility.
Given the size of the demolition industry, its heavy burden on the environment, and the aforementioned challenges, it has become a hotbed of research and development.
Supporting that, the USGBC LEED scoring system awards points for landfill diversion. Technological innovations include advanced sorting systems to efficiently segregate materials, including applying machine learning, AI, and robotics to visually identify and sort waste; using stone waste in engineered stone lumber; and incorporating asphalt shingle recycling into paving materials. In each case, the economics of production and market-competitive pricing have yet to be achieved.
Felix Heisel, assistant professor and director of the Circular Construction Lab (CCL) at Cornell University’s College of Architecture, Art, and Planning, breaks down the challenge of demolition and material recovery into two parts: how to best reduce waste when existing buildings are demolished, and how to build new structures with future deconstruction in mind—making reuse, the desired “cradle to cradle” circular economy, far more achievable.
“We have to build today for disassembly and reuse in the future.”
—Felix Heisel
“We call the current approach ‘urban mining,’” says Heisel about methods now used to reclaim materials from demolition sites. “But as with other forms of mining, there is waste involved. It can be a dirty process because current buildings are not designed to be deconstructed.” The key challenge is waste separation and material recovery in an economically viable process.
Heisel directed the CCL in 2022 to deconstruct a small apartment structure in Ithaca, New York, one of 11 similar structures built in the early 1900s and being demolished to make way for denser, modern housing. The situation allowed a side-by-side comparison between traditional and his more progressive, save-it approaches.
Known as the Catherine Commons Deconstruction project, portions of the test building were cut and lifted whole onto flatbed trucks. Sections of roofs, walls with windows and door frames, and staircases were cut and kept intact manually, lifted by cranes, and shipped to an off-site sorting facility. They were able to accomplish this task in five days—per the developer’s mandate—while the other structures each fell to the demolition machinery within two to three days. Time is money for developers.
Other stakeholders in the project, which included artists and preservationists, spoke of embodied skills and design in the 100-year-old pieces and the value they bring to reuse—complementing the climate-conscious embodied carbon calculus.
But Heisel looks to a future in how this process can be much more efficient and effective. “We have to build today for disassembly and reuse in the future.”
While that might seem a far-off time, Heisel finds great interest in the approach among architecture and design students at Cornell. To feed that interest, CCL created RhinoCircular, a plug-in to the Rhino 3D modeling tool used in construction and design. This plug-in summarizes relevant information in building materials to address sustainability factors, including material reuse. “It calculates the circularity of a whole design,” Heisel explains. “This feedback triggers questions in the design process. One metric is the percent of materials that can be reused to close the loop.”
Some of the material saved from the Deconstruction Project in Ithaca, supported by the Cornell Council for the Arts and other university organizations, was turned into an art installation called Circulating Matters. Measuring approximately 14 feet in length and width and 16 feet high, it’s a pyramidal ascension of 7 wooden steps, with wood columns rising from each step corner to a center plateau. First displayed at the 2022 Cornell Biennial on the university’s Art Quad, it is now sited at the Architecture and Sculpture Park Art Omi in Ghent, New York.
Back in Virginia, the 20,000-pound Robert E. Lee statue, removed from its pedestal in Charlottesville, was melted down into bronze ingots in a project called Swords Into Plowshares. Similar to Circulating Matters, the ingots will be reformed into an art piece with a specific goal, to “create a more inclusive public art installation,” according to a report on National Public Radio.
We know that all things over time—buildings as well as statues—pass. But art alone, it is said, endures.
