The U.S. Demolishes Buildings and Rebuilds Them at an Astonishingly Unsustainable Rate
The following is an excerpt from the new book The Past and Future City by Stephanie Meeks & Kevin C. Murphy (Island Press, 2016):
How well do you remember February 1985? I know that for more than a third of Americans—who are under the age of thirty-two—the answer is not at all. Journey back with me if you can. Ronald Reagan had just started his second term in ofï¬ce. Nelson Mandela was still in jail. Foreigner’s “I Want to Know What Love Is” and George Michael’s “Careless Whisper” were the big hits on the radio. At the movies, Harrison Ford was hiding out in Amish country in Witness, and the Brat Pack were ï¬guring one another out and falling in love in The Breakfast Club. I myself was in college that month, at the University of Colorado Boulder.
That month didn’t seem like a particularly historic one at the time, but it holds a grim distinction. As of this writing, more than thirty years later, February 1985 was the last month that the surface temperature on Earth was colder than the twentieth-century average. Every single month since then has been warmer than that average. Writing on this phenomenon in July 2012, 327 months into the streak, author Bill McKibben pointed out in Rolling Stone that “the odds of [this] occurring by simple chance were 3.7 x 1099, a number considerably larger than the number of stars in the universe.” That was already years ago.
A few years before writing that piece for Rolling Stone, McKibben started an advocacy website called 350.org, so named after the ï¬ndings in a 2007 study by National Aeronautics and Space Administration (NASA) scientist James Hansen. The amount of carbon dioxide in the atmosphere before the Industrial Revolution was 275 parts per million (ppm). By 2008, it had reached 385 ppm. This number is important because more carbon in the atmosphere means more heat is trapped on Earth, thus warming the planet.
Trying to ï¬gure how much atmospheric carbon would be too much, Hansen determined that “if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that.” Higher carbon dioxide levels, McKibben and Hansen pointed out, would mean melting ice caps and rising oceans, “something that would shake the foundations of the human enterprise should it happen again.” The line had to be drawn, here and now. “Three hundred and ï¬fty,” McKibben said, “is the number every person needs to know.”
In March 2015, for the ï¬rst time in recorded history, a reading of 400 ppm was measured for the entire month. By November 2015, scientists warned that 400 ppm and above would soon become a “permanent reality.” Today, 350—the number that could very well mean catastrophe—is in the rearview mirror.
Also in early 2015, two separate and independent analyses of climate data by NASA and the National Oceanic and Atmospheric Administration determined that 2014, the year that had just passed, was the warmest year ever recorded, going back to 1880. What’s more, all ten of the hottest years on record had taken place since 1998. That dubious record lasted all of 365 days. A year later, scientists announced that 2015 had blown past 2014 as the hottest year ever, by the biggest margins ever seen. Said one scientist at the National Center for Atmospheric Research, “The whole system is warming up, relentlessly.” And 2016 began even hotter still.
I know there are those on Capitol Hill, in some state legislatures, and on talk radio who still question whether climate change is actually happening, but that is not a luxury we really have time for anymore. In the ï¬eld of preservation, we are already starting to experience and grapple with climate change in very concrete ways. Beloved destinations are confronting the new reality of rising sea levels. Powerful superstorms like Katrina and Sandy are damaging historic places with increasing regularity. Roughly one hundred of the National Park Service’s more than four hundred park units are already experiencing climate-related transformations.
Climate change is real. It is happening. Its impact on all our communities is only going to grow stronger in the years to come. To address it head-on—and save the most important historic place there is, our planet—we are going to have to reshape our cities and neighborhoods to reduce carbon emissions and make them more green, sustainable, and energy efï¬cient. Historic preservation has a huge part to play in this transformation.
Even beyond all the many social, economic, and community beneï¬ts of historic fabric, here is where reusing our older buildings becomes an absolute necessity for our future.
The Greenest Buildings . . .
Although climate change has added additional urgency to our efforts, the idea that older buildings have a key role to play in forging greener, more sustainable communities has been around for a while. In 1980—when President Jimmy Carter ï¬rst made energy efï¬ciency a national focus—the National Trust had a poster that showed a building in the shape of a gasoline can. It read: “It takes energy to construct a new building—it saves energy to preserve an old one.” That, in a sentence, is why preservation is so fundamentally important to our future health and well-being.
According to the US Department of Energy, building operations account for 41 percent of the nation’s energy consumption, 72 percent of its electricity consumption, and 38 percent of its carbon dioxide emissions. In urban areas, these numbers are even higher. Commercial buildings are estimated to be responsible for 70 percent of Chicago’s total carbon emissions and 80 percent of New York’s. Given these statistics, there is no way to feasibly address the climate crisis without changing how we manage our urban landscape.
At the same time, roughly one billion square feet of buildings are demolished and replaced every year in the United States. According to an analysis by the Brookings Institution, the country is in the midst of demolishing and replacing 82 billion square feet of existing space—nearly one-fourth of the existing building stock—by 2030.
That is an astonishing amount of waste. In fact, the energy used to demolish and rebuild that much space could power the entire state of California for a decade! According to a formula produced for the Advisory Council on Historic Preservation, about 80 billion British thermal units (Btus) of energy are embodied in a typical 50,000-square-foot commercial building. As my predecessor Richard Moe pointed out in 2008, that’s “the equivalent of 640,000 gallons of gasoline. And if you tear the building down, all the energy that went into creating the building is wasted. Demolishing that same 50,000-square-foot building also creates nearly 4,000 tons of waste. That’s enough debris to ï¬ll 26 railroad boxcars—a train nearly a quarter of a mile long, headed for a landï¬ll that is already almost full.”
It simply does not make sense to recycle cans and newspapers to save energy and not recycle buildings. As architect and green advocate Carl Elefante wrote in a 2009 essay, “Taking into account the massive investment of materials and energy in existing buildings, it is both obvious and profound that extending the useful service of life of the building stock is common sense, good business, and sound resource management.” Put simply, he said, “the Greenest Building is the one that’s already built.”
This holds particularly true when you consider that it takes decades for even most of the new efï¬cient buildings to recover the carbon that is expended in their construction. In short, we cannot build our way to sustainability. In a perfect world, every new building going forward would be net zero—meaning it produces as much as energy as it consumes. But even if that were the case, it would have the same effect over a full year as cutting energy use of all existing buildings by just 1 percent. “Seeking salvation through green building,” wrote Elefante, “fails to account for the overwhelming vastness of the existing building stock. [That] is the elephant in the room: Ignoring it, we risk being trampled by it. We cannot build our way to sustainability; we must conserve our way to it.”
That is why what we do with our existing fabric is so important. In our rush to embrace green construction, we cannot lose sight of the tremendous value of saving and reusing buildings that have already been built.
In January 2012, the National Trust’s Preservation Green Lab published its ï¬rst major report, entitled “The Greenest Building: Quantifying the Environmental Value of Building Reuse”, on this nexus of preservation and sustainability. The Green Lab ï¬rst looked at the full life-cycle—from the extraction and transportation of the raw materials used in construction through decades of use—of different types of buildings, such as single-family and multifamily homes, schools, warehouses, and ofï¬ces.
To ensure that their data accounted for different climates and a variable mix of energy sources, Green Lab researchers surveyed buildings in four US cities: Chicago, Atlanta, Phoenix, and Portland, Oregon. Using this life-cycle analysis methodology, they then compared the relative environmental impacts of building reuse and renovation versus demolition and new construction over the course of a seventy-ï¬ve-year life span.
In almost all cases, when they compared buildings of similar size and functionality, they found that building reuse yields fewer environmental impacts than new construction. In fact, depending on the type of structure, it takes between ten and eighty years for a new “green” building that is 30 percent more energy efï¬cient than the existing one to make up for the amount of carbon unleashed through its construction. These ï¬ndings accord with other studies on the subject. For example, a report by Britain’s Empty Homes Agency found that it takes thirty-ï¬ve to ï¬fty years for a new, green home to recover the initially expended carbon as well.
The range of environmental savings varies based on building type, location, and presumed level of energy efï¬ciency, but when comparing buildings with the same energy performance level, the environmental savings from reuse are between 4 and 46 percent over new construction. The one exception is when industrial warehouses are converted into multifamily residential units, which resulted in a 1 to 6 percent greater environmental impact. Foremost among the reasons for this difference are the amount and type of materials used for rehab, which can signiï¬cantly mitigate or even cancel out the energy savings from recycling buildings.
So it is important to use the right materials—and minimize the amount of new materials—in renovation projects. If done correctly, however, the impact reductions of reusing old buildings can be substantial, particularly when taken to scale.
To take just one example, if the city of Portland, Oregon, were to retroï¬t and reuse the single-family homes and commercial ofï¬ce buildings that it is otherwise likely to demolish over the next ten years, based on its demolition rates from 2003 to 2011, the potential impact reduction would total approximately 231,000 metric tons of carbon dioxide. This ï¬gure is about 15 percent of Portland’s stated carbon reduction target over the next decade. The city could save 15 percent immediately just by conserving and reusing its already existing buildings.
What is true in Portland can be true all over the United States. In 2014, as part of the United Nations Climate Summit, 451 cities around the world—including 122 in the United States—pledged to reduce their carbon emissions and begin preparing for climate change. Similarly, in 2015, a number of US and Chinese cities agreed to deep cuts in carbon emissions as part of a bipartisan climate summit in Los Angeles—a city that, like New York, has pledged to cut its emissions by 80 percent by 2050. As noted earlier, Seattle has gone a step even further and declared that it will be completely carbon neutral by 2050. All these cities can get a leg up on reaching these necessary emissions cuts by stopping demolition and working with their existing building fabric.
Ultimately, we can’t build our way out of the global warming crisis. We have to save our way out. That means we have to make better, wiser use of what we’ve already built.
The Past and Future City: How Historic Preservation is Reviving America's Communities Stephanie Meeks and Kevin C. Murphy © Island Press