Demolition of an existing structure means wasting all the energy put into the creation of the materials. The destruction itself also costs energy and the waste must be disposed of in landfills. Add that to the energy and emissions required to make, transport and assemble materials for a brand new building, and it’s easy to see how using what’s already built is the most sustainable option.
Susan Piedmont-Palladino, director of the Washington-Alexandria Architecture Center at Virginia Tech, spoke to WIRED from an office building that embodies this premise. It was built in 1909 as an elementary school for girls. “It’s a brick building, but the floor structure is all wood that would have been cut in the early 1900s,” she says. “Here I am in this building with that carbon locked in and useful. If we were to demolish it, all this stuff would have to go to landfill or reclamation.”
Material savings
It is now possible to quantify the metric tons of carbon that could be saved by not rebuilding from scratch, which can help customers or planners choose the greener option. Most architectural and engineering firms now have access to software such as OneClick LCA or EC3 that can simulate scenarios for reusing existing materials and structures in a new project. This software can also be used to assess the financial value of old foundations, concrete, aluminum, wood and other material and plan how to incorporate parts of the existing structure. If a structure cannot be saved, the materials can sometimes be reused. For example, a certain type of concrete can be broken down and a different concrete style can be made of it.
“This is approaching common practice,” said Christopher Pyke, senior vice president at the U.S. Green Building Council and professor of urban planning at Georgetown University. “It has been a fundamental part of the LEED rating system for the past five years and in Europe it is being codified in regulation.” LEED plates on shiny new buildings can now reflect that not everything about a new construction is new or that the structure has been adopted entirely from an old building.
A concept espoused by some European architects views buildings themselves as material banks – structures that store and store materials for future use. Some buildings are designed to be easier to tear down in the future, so that the materials are easily accessible for new projects.
While Piedmont-Palladino is intrigued by material banking, he is more drawn to the inverse idea: building for long-term yet adaptable sustainability. To make architecture more sustainable, people’s mindsets have to change, she says, and they have to resist the lure of shiny green baubles.
“Architecture very quickly broke it down and made it new. The more people associate architecture with trends and fashion, the more dangerous it becomes. Same with urban planning,” she says. “You are not the last people to be involved in this building.”
Take the graduation project of Ludwig Mies van der Rohe, one of the most important architects of the 20th century, but fading in popularity. He created a modern, minimalist “skin and bones” style that shaped the American urban landscape for the last 25 years of the 20th century. The Martin Luther King Jr. Library in Washington, D.C., one of his last projects, was not completed until three years after his death, in 1972.
“It went through the stock market crash of reputation. Everyone loved it and then everyone hated it,” Piedmont-Palladino says. By the early 2000s, the library was neglected and reviled by borrowers and librarians for its dark, cramped, and unusable spaces. renovation early, many in D.C. called for it to be demolished and built from scratch.Piemonte-Palladino, on the selection committee for new architects for the project, was one of many who objected, both on grounds of sustainability and aesthetics. “Mies, he’s hard to love. But were we really going to demolish this project that represented the modernism coming to Washington?
In the end they didn’t. The library, which reopened at the end of 2020, looks shiny and new. The architects added wood, curves, windows and sound, making the place warm and beautiful instead of austere and intimidating. But the structure kept its Mies facade, its history and its embodied carbon.
