With the exception of the first underestimated stat, this is a topic seldom discussed, yet highly overlooked.
All the best for a great New Year! Natalia THE IGNORED GREENNESS OF HISTORIC PRESERVASION [From a speech at the National Building Museum] RICHARD MOE, NATIONAL TRUST FOR HISTORIC PRESERVATION - Up to now, our approach to life on this planet has been based on the assumption that "there's plenty more where that came from." With our environment in crisis, we have to face the fact that there may not be "plenty more" of anything – except trouble. In the face of that realization, we're challenged to find a way of living that will ensure the longevity and health of our environmental, economic, and social resources. . . 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. . . 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 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. . . 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. 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. Instead of focusing on generalities, let's look at a specific building – like the one we're in right now. It's estimated that the National Building Museum contains about 1.5 million bricks. When you consider how much energy it took to make all those bricks, plus how much it took to manufacture the other materials, then transport them to this site and put them all together in this marvelous structure, the total embodied energy in this building is the equivalent of nearly 2 million gallons of gasoline. If we assume the average vehicle gets about 21 miles to the gallon, that means there's enough embodied energy in this building to drive a car about 42 million miles. All of that energy would be wasted if this building were to be demolished and landfilled. What's more, the demolition itself would require the equivalent of more than 8,700 gallons of gas – and it would create nearly 11,000 tons of waste. 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. . . Most recent efforts by the green community place heavy emphasis on new technologies rather than on tried-and-true preservation practices that focus on reusing existing buildings to reduce the environmental impacts associated with demolition and new construction. The most popular green-building rating system, the Leadership in Energy and Environmental Design, or LEED program developed by the U. S. Green Building Council, was designed principally for new construction – underscoring the fact that words like "rehabilitation" and "reuse" haven't had much resonance in the green-building lexicon. This emphasis on new construction is completely wrong-headed. The statistics I cited earlier tell us clearly that buildings are the problem – but incredibly, we propose to solve the problem by constructing more and more new buildings while ignoring the ones we already have. 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. It's often alleged that historic buildings are energy hogs – but in fact, some older buildings are as energy-efficient as many recently-built ones, including new green buildings. Data from the U.S. Energy Information Agency suggests that buildings constructed before 1920 are actually more energy-efficient than buildings built at any time afterwards – except for those built after 2000. Furthermore, in 1999, the General Services Administration examined its buildings inventory and found that utility costs for historic buildings were 27% less than for more modern buildings. It's not hard to figure out why. Many historic buildings have thick, solid walls, resulting in greater thermal mass and reducing the amount of energy needed for heating and cooling. Buildings designed before the widespread use of electricity feature transoms, high ceilings, and large windows for natural light and ventilation, as well as shaded porches and other features to reduce solar gain. Architects and builders paid close attention to siting and landscaping as tools for maximizing sun exposure during the winter months and minimizing it during warmer months. . . I'm not suggesting that all historic buildings are perfect models of efficient energy use – but, contrary to what many people believe, older buildings can "go green." The marketplace now offers a wide range of products that can help make older buildings even more energy-efficient without compromising the historic character that makes them unique and appealing. And there's a large and growing number of rehab/reuse projects that offer good models of sustainable design and construction. More recent buildings – especially those constructed between the 1950s and 1980s – pose a greater challenge. Many of them were constructed at a time when fossil fuels were plentiful and inexpensive, so there was little regard for energy efficiency. In addition, they often include experimental materials and assemblies that were not designed to last beyond a generation. Today, these buildings make up more than half of our nonresidential building stock. Because of their sheer numbers, demolishing and replacing them isn't a viable option. We must find ways to rehabilitate these buildings and lighten their environmental footprint while still protecting their architectural significance. . . t makes no sense for us to recycle newsprint and bottles and aluminum cans while we're throwing away entire buildings, or even entire neighborhoods. This pattern of development is fiscally irresponsible, environmentally disastrous and ultimately unsustainable. http://www.nationaltrust.org/news/2007/20071213_scully.html --- avast! Antivirus: Outbound message clean. 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