The Greenest Building Is One That Already Exists

“Yale University has reduced its greenhouse gas emissions by 17% since committing to a steep reduction in 2005, President Richard C. Levin reported today in a speech at the University of Copenhagen,” proclaims a Yale University press release of January 21, 2008 announcing Yale’s leadership in campus sustainability. The press release continues, “Levin’s speech, “Leading by Example: Creating a Sustainable Campus,” is the first of a series of lectures on climate change sponsored by the University of Copenhagen as a prelude to the United Nations’ climate summit in Denmark in 2009.”

The following speech (excerpted) was delivered by Richard Moe, President of the National Trust for Historic Preservation, at the National Building Museum in Washington, D.C. on the occasion of receiving the Vincent Scully Prize on December 13, 2007.

“… I am especially honored to have this prize awarded by Vince Scully. He is a hero of mine, as he is to so many of you, and to so many others who appreciate great design and great architecture. I don’t know of anyone who has done more to foster a better understanding and appreciation of all aspects of our built environment, or who has inspired more students to pursue excellence in improving that environment. Vince is a Trustee Emeritus of the National Trust and … I will be ever proud of this award which bears his name.

When you strip away the rhetoric, preservation is simply having the good sense to hold on to things that are well designed, that link us with our past in a meaningful way, and that have plenty of good use left in them.

Because it necessarily involves the conservation of energy and natural resources, historic preservation has always been the greenest of the building arts…It’s all about sustainability.

The United States is a big part of the problem. We have only 5% of the world’s population, but we’re responsible for 22% of the world’s greenhouse gas emissions that are the leading cause of climate change. Much of the debate on this subject usually focuses on the need to reduce auto emissions. But according to the EPA, transportation–cars, trucks, trains, airplanes–accounts for just 27% of America’s greenhouse gas emissions, while 48%–almost twice as much–is produced by the construction and operation of buildings. If you remember nothing else I say tonight, remember this: Nearly half of the greenhouse gases we Americans send into the atmosphere comes from our buildings. In fact, more than 10% of the entire world’s greenhouse gas emissions is produced by America’s buildings–but the current debate on climate change does not come close to reflecting that huge fact. The message is clear: Any solution to climate change must address the need to reduce emissions by being smarter about how we use our buildings and wiser about land use.

The retention and reuse of older buildings is an effective tool for the responsible, sustainable stewardship of our environmental resources–including those that have already been expended. I’m talking about what’s called “embodied energy.”

Here’s the concept in a nutshell: Buildings are vast repositories of energy. It takes energy to manufacture or extract building materials, more energy to transport them to a construction site, still more energy to assemble them into a building. All of that energy is embodied in the finished structure–and if the structure is demolished and landfilled, the energy locked up in it is totally wasted. What’s more, the process of demolition itself uses more energy–and, of course, the construction of a new building in its place uses more yet.

Let me give you some numbers that will translate that concept into reality.

▪ According to a formula produced for the Advisory Council on Historic Preservation,
about 80 billion BTUs of energy are embodied in a typical 50,000-square-foot commercial building. That’s the equivalent of 640,000 gallons of gasoline. If you tear the building down, all of that embodied energy is wasted.

▪ What’s more, demolishing that same 50,000-square-foot commercial building would create nearly 4,000 tons of waste. That’s enough debris to fill 26 railroad boxcars–that’s a train nearly a quarter of a mile long, headed for a landfill that is already almost full.

▪ Once the old building is gone, putting up a new one in its place takes more energy, of course, and it also uses more natural resources and releases new pollutants and greenhouse gases into our environment. Look at all the construction cranes dotting the Washington skyline, and consider this: It is estimated that constructing a new 50,000-square-foot commercial building releases about the same amount of carbon into the atmosphere as driving a car 2.8 million miles.

One more point: Since 70% of the energy consumed over a building’s lifetime is used in the operation of the building, some people argue that all the energy used in demolishing an older building and replacing it is quickly recovered through the increased energy efficiency of the new building–but that’s simply not true. Recent research indicates that even if 40% of the materials are recycled, it takes approximately 65 years for a green, energy-efficient new office building to recover the energy lost in demolishing an existing building. And let’s face it: Most new buildings aren’t designed to last anywhere near 65 years.

Despite these surprising statistics and many more like them, we persist in thinking of our buildings as a disposable–rather than a renewable–resource. A report from the Brookings Institution projects that by 2030 we will have demolished and replaced 82 billion square feet of our current building stock, or nearly 1/3 of our existing buildings, largely because the vast majority of them weren’t designed and built to last any longer. That much demolition will create a lot of debris. If we didn’t recycle any of the building materials, we’d be left with 5.5 billion tons of waste. That’s enough debris to fill almost 2,500 NFL stadiums.

How much energy will it take to demolish and replace those buildings? Enough to power the entire state of California–the 10th largest economy in the world–for 10 years. On the other hand, if we were to rehab just 10% of these buildings, we would save enough energy to power the State of New York for well over a year.

It all comes down to this simple fact: We can’t build our way out of the global warming crisis. We have to conserve our way out. That means we have to make better, wiser use of what we’ve already built.

Anthropologist Ashley Montague has said that the secret to staying young is to die young–but the trick is to do it as late as possible. All over the United States, people are showing that old buildings put to new uses can stay young to a ripe old age. If that’s not sustainability, I don’t know what else to call it. Still, too many people just don’t see the connection. They don’t yet understand that preservation must be an integral part of any effort to encourage environmental responsibility and sustainable development.

Here’s what we have to keep in mind: No matter how much green technology is employed in its design and construction, any new building represents a new impact on the environment. The bottom line is that the greenest building is one that already exists.”