the greenest building is one that is already built

The latest issue of Preservation, the magazine of the National Trust, is THE GREEN ISSUE, all about the myriad energy and waste factors associated with both new and old buildings. The recent green wave has tended to create a perception of a huge gulf between new green buildings and old, drafty, energy-wasters. The hype that accompanied the campaign to build Mansfield's new high school is a prime example of that perception. A more careful analysis of the energy it takes per square foot to maintain a new, LEED rated building, vs. a pre 1920s building is about the same. And the consideration of "embodied energy", the energy already bound up in preexisting buildings or used to construct a new green building, can overwhelm the energy-conservation advantages in new green construction. Wayne Curtis' article, A Cautionary Tale, quotes Mike Jackson, chief architect with the Illinois Historic Preservation Agency: "if embodied energy is worked into the equation, even a new, energy-efficient office building doesn't actually start saving energy for about 40 years. And if it replaces an older building that was knocked down and hauled away, the break-even period stretches to some 65 years, since demolition and disposal consume significant amounts of energy. There's no paybacke here," Jackons said. "We're not going to build anything today that's going to last 65 years."
Architect Carl Elefante said it more simply in last summer's National Trust Forum Journal: "THE GREENEST BUILDING IS ONE THAT IS ALREADY BUILT".