The ultimate in ‘green’ construction

Future-Proof: Navigate Threats, Seize Opportunities at ICNY 2018 | Jan 22-26 at the Marriott Marquis, Times Square, New York

What's the greenest way to build? Using natural, renewable resources? Using salvaged building materials? Or using the same stuff you've always used, but which some corporate PR firm has managed to repackage as "green"?

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...