These are all ways to profess greenness, some effective, some merely gestural. But by far the greenest way to build is to adapt structures that already exist — and that’s one avenue in which we Americans still fall woefully short.
We are, after all, a young nation built largely from scratch, and we consider it normal for our built environment to be constantly in flux. Here, it’s common for buildings to be destroyed after 50, 30 or even 10 years of use — and in the face of rapid social change, the expected life of new buildings will likely get shorter rather than longer.
One study has pegged the average lifespan of American buildings at just shy of 50 years. Compare this to the Old World, where a building’s life is measured in centuries rather than decades. The average life of an English building, for example, is 132 years. The typical lifespan of buildings on mainland Europe is probably even longer if we discount the effects of two world wars.
There was a time when Americans, too, built with permanence in mind. But no more. Our modern obsession with speed and short-term profit leads us to build quickly and on the cheap to ensure the quickest monetary return possible. Such thinking leads to a vicious cycle of wastefulness: Because permanence is considered irrelevant, newer buildings naturally wear out quickly, often to be demolished and replaced by structures that are even shoddier and more temporary. It’s no help to claim that these new buildings are green, as their construction is an unnecessary waste in the first place.
Preserving and reusing older, well-built existing structures, on the other hand, is the ultimate expression of true green design, as it requires relatively little additional expenditure of energy compared to new construction. But there are other, subtler reasons to preserve what already exists.
It’s generally true that buildings predating World War II are more opulent than their modern counterparts, making use of materials that, due to depletion or economics, are no longer part of the building canon. But what is seldom appreciated is that such buildings also embody an enormous storehouse of labor — much of it of a kind our society can no longer afford. Many once-ubiquitous building trades have all but vanished over the last century — from stonemasons to stained-glass makers, from plasterers to gilders — and the fruits of their labors remain in every extant building, essentially frozen in time.
These skills won’t be coming back, except in their current status as boutique trades carrying astronomical costs. Hence, destroying an old building doesn’t just squander precious physical resources; it also negates forever a huge investment of skilled work that’s no longer affordable and in some cases no longer even obtainable. Obliterating this legacy of the past — the ultimate nonrenewable resource — is more tragic than the waste of any precious material.