THE GREENEST BUILDING? One That's Already Built
/If the biggest threat to human survival is climate change, then American construction is probably the industry most responsible for causing it. Every new construction site represents the climate being changed, the environment being degraded, energy being consumed, and irreplaceable natural resources being used.
BUILDING DEMOLITION
According to the U.S. Energy Information Statistics Center, 48% of America’s greenhouse gas emissions come from the construction and operation of buildings. That’s almost twice the amount of emissions that come from cars, trucks, and airplanes combined.
While the industry and transportation sectors each consume about 26% of our energy, the construction sector uses 48%. And, according to National Association of Homebuilders, one 2,000 square-foot home uses up to 1.5 acres of forest and for each ton of Portland cement produced, one ton of CO2 is emitted into the atmosphere.
In landfills, somewhere between 35-45% of the waste stream comes from construction and demolition -- 4.3 millions tons of construction and demolition are generated in California alone. According to Place Economics in Washington, while we dutifully recycle aluminum cans, demolishing 10,000 square feet of old buildings wipes out the benefit of recycling 2,688,000 cans.
The building industry needs to be smarter. If there is any hope for survival, we need to radically change the way we use our land and how we construct and operate buildings.
HISTORIC DISTRICT, ALAMEDA, CA
Even a brief look at how buildings can better conserve energy and resources reveals the importance of existing buildings: existing buildings are the repository of so much energy (also called “embodied energy”), it’s easy to understand why preserving and reusing them is the ultimate recycling process. The greenest thing anybody can do is to continue the life of a building whose resources have already been extracted from our planet and whose resources don’t need to go into a useless landfill. The practice of rehabilitating, restoring, and/or reusing older buildings is conservation or historic preservation. Preservation has always been the greenest of building arts and the environmental crisis is now mandating us to practice it.
Please note, however, that “green building” is an oxymoron. According to Jane Powell, author of many rehabilitation books, any kind of building – including remodeling – uses up resources, even if those resources are recycled or salvaged. But retrofitting an older building for better energy efficiency, lower water use, improved life safety features, and/or new activities, is still much better – and much greener – than building new.
REPURPOSED BOAT HOUSE, OAKLAND, ca
Construction Myths
On the eve of the National Trust’s publication of sustainability standards, it might be useful to review some of the myths related to reusing older buildings. The Trust’s study, “The Environmental Value of Building Reuse,” found that building reuse typically offers greater environmental savings than demolition and new construction. These environmental savings, in turn, reduce climate change impacts. In contrast, it can take between 20 to 30 years for a new, energy-efficient building to overcome (through efficient operations) the negative carbon impacts created by its construction.
Further, the study found that reusing existing buildings is good not only for the environment, but also for the economy and the community. At a time when foreclosure and unemployment rates remain high, existing buildings are a good investment for communities. Historic preservation has a 32-year track record of creating 2 million jobs and generating $90 billion in private investment. Studies also show that residential rehabilitation creates 50% more jobs than new construction. And, according to the California Preservation Foundation, cities with historic districts have more diversified economies. These districts, in turn, attract more cultural visitors who spend more tourist dollars because they typically visit longer. Finally, the immeasurable benefit of rehabilitated buildings is that they create community pride and enhance the quality of life.
Embodied Energy
Hopefully, everyone will continue recycling aluminum cans in spite of the small environmental benefits this produces. However, for those of us in the building industry, it’s time to seriously review our activities and their impact on our planet.
According to the Advisory Council on Historic Preservation, 80 billion BTUs are embodied in a 50,000 square-foot building, the equivalent of 640,000 gallons of gasoline. If that building is torn down, all that embodied energy is wasted. What’s more, the demolition process uses more energy. And the debris would create 4,000 tons of waste, enough to fill 26 railroad boxcars. Constructing a similarly-sized new building would use even more energy and more natural resources, releasing more pollutants into the environment. Constructing this replacement building would emit the carbon equivalent of driving a car 2.8 million miles.
Recent research indicates that even if 40% of the materials are recycled, it takes approximately 65 years for a new, efficient office building to recover the energy lost in demolishing an existing building. And new buildings aren’t designed to last anywhere near 65 years, even if they are “green-rated.”
NEW CONSTRUCTION
Green “ratings” are another misnomer when it comes to buildings. The most popular system - Leadership in Energy and Environmental Design (LEED) - was designed for new construction and offers few points for rehabilitating an existing building. Under the current LEED rating system, for example, reusing 75% of an existing building core and shell is assigned the same value as environmentally-friendly carpet. Obviously, the U.S. Green Building Council, among other public policy groups, need to revise their standards.
Green Building is an Oxymoron
Current American policies and green building practices still emphasize new construction and this moves us in the wrong direction. Instead, we need better programs and incentives for energy upgrades and encouraging reuse of older buildings.
According to Richard Moe, past President of the National Trust, in spite of these important statistics on demolition and new construction, our society persists in thinking of buildings as disposable resources rather than renewable ones. By 2030, we will have demolished and replaced nearly 1/3 of our current building stock, creating enough debris to fill 2,500 NFL stadiums.
How much energy does this represent? According to Moe, enough to power California (the 10th largest economy in the world) for 10 years. By contrast, if we rehabilitate just 10% of these buildings, we could power New York for over a year.
DISPOSABLE HOMES?
The facts are in – no matter how much green technology is employed, any new building represents a new impact on the environment. It makes no sense for us to recycle newspapers, bottles, and cans while we’re throwing away entire buildings and neighborhoods. It’s fiscally irresponsible and entirely unsustainable.
The simple fact is that we cannot build our way out of global warming, we need to conserve our way out. We have to make better and wiser use of what we’ve already built: the bottom line is that the greenest building is one that already exists.
