"Many of the inner-city neighborhoods that began their decline in the 1960s consisted of sturdily built, turn-of-the-century row houses, tough enough to withstand being broken up into apartments, and requiring relatively little upkeep. By comparison, modern suburban houses, even high-end McMansions, are cheaply built. Hollow doors and wallboard are less durable than solid-oak doors and lath-and-plaster walls. The plywood floors that lurk under wood veneers or carpeting tend to break up and warp as the glue that holds the wood together dries out; asphalt-shingle roofs typically need replacing after 10 years. Many recently built houses take what structural integrity they have from drywall—their thin wooden frames are too flimsy to hold the houses up."

That's progress for you.