The hunt for dirt is not limited to the Twin Cities. After builders across the country spent decades feeding acre after acre of raw land into the maw of demand for single-family homes, the housing crash left them with a land surplus so large that lots were selling for pennies on the dollar. At the peak of supply, in 2009, there were enough lots to last almost eight years, according to MetroStudy, a firm that tracks housing data. Now there is less than four year’s worth, and only about a quarter of that is in the more desirable A- or B-rated locations.

“We have gone from a situation where five years ago everyone was saying, ‘There’s too many lots,’ to today, builders are literally crying on our shoulder saying, ‘There’s not enough lots. We can’t find any,’” said Bradley F. Hunter, the chief economist at MetroStudy.

The shortage of lots is slowing the housing recovery, the National Association of Home Builders said last week. In August, 59 percent of builders surveyed said lot supply was low or very low, the association said. Housing is a critical driver for the economy, not just because of the jobs and supplies needed to build homes but also the appliances and furnishings that new occupants buy.

At the peak of the housing boom, builders were finishing more than 1.6 million single-family houses a year. That number plunged to less than half a million during the recession. This year, the industry is on track to complete more than 570,000 homes, still substantially below the level considered necessary to replace aging homes and provide for new households. A return to more normal rates of construction would substantially lift the economy’s anemic growth rate of about 2 percent over the last year.