Although the housing crisis is nearly two years old, many banks had refrained from cracking down on small home builders.

They are starting to do so, and a wide swath of the industry could be forced out of business in the next few years. The trouble is concentrated especially in the Sun Belt, the scene of so much overbuilding.

Not only have new-home sales stagnated, but builders confront a rising wave of foreclosed properties coming to market at prices below the cost of building a new home. To move houses, they have to mark them down to less than the cost of construction.

The convergence of these problems is bringing many small and medium-size builders — who account for about 70 percent of new-home construction in the United States — to their knees.

New York Times