As W.B. Yeats could have put it, ours is no country for old buildings. Each year, countless aging and outdated structures are dispatched by our $4 billion demolition industry. Even the recent economic retrenchment has hardly altered the nation’s out-with-the-old, in-with-the-new mind-set. In 2010 alone, an estimated 104 million tons of materials flowed in from project sites all over the country, accounting for as much as 40 percent of the U.S.’s annual solid-waste stream. The garbage comprises not only rubble and rotting beams, but also countless odds and ends from new construction such as cast-off nails and packaging. So whether they’re putting something up or taking something down, architects are indirectly making a mess.