Sustainable Design

Preservation is Sustainability
by Lloyd Alter, Toronto on 04.07.08
DESIGN & ARCHITECTURE | treehugger.com

Speaking at Bernard Maybeck's historic First Church of Christ, Scientist in Berkeley, the President of the National Trust for Historic Preservation, Richard Moe, made an historic speech about how saving old buildings is not about the past, but the future.

In the speech he notes that existing buildings"are vast respositories of energy." "It takes energy to manufacture to extract building materials, more energy to transport them to a construction site, still more energy to assemble them into a building," he says. "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." He calculates that even if 40% of the materials in a new building are recycled, it would take 65 years for "green, energy-efficient new office building to recover the energy lost in demolishing an existing building,

From the speech, on the meaning of preservation:

"I'll begin with a reminder of what historic preservation is all about. 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."

On current planning:

One of the first and most important things that must happen is a thoroughgoing revision of current government policies that foster unsustainable development. For decades, national, state and local policies have facilitated – even encouraged – the development of new suburbs while leaving existing communities behind. As a result, an epidemic of sprawl ravages the countryside, devouring open space and demanding new infrastructure. Look at almost any city in the country, and you'll see new houses springing up in rural areas that are underserved by roads and public services – while in the urban core, disinvestment has left viable housing stock abandoned in areas where infrastructure is already in place, already paid for.

It 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.

On old buildings being green:

"The key phrase is "sustainable stewardship."

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 building would create nearly 4,000 tons of waste. That's enough debris to fill 26 railroad boxcars – 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. It is estimated that constructing a 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: You might think that all the energy used in demolishing an older building and replacing it is offset by 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." Read it all at ::preservation nation via ::WFFA

See also Big Steps in Building: Ban Demolition and Demolition by Neglect: Use It or Lose It