The number of building permits issued and homes started jumped in September to levels not seen since July 2008, the U.S. Census Bureau reported Wednesday, adding more evidence that the housing market is in rebound.

Housing permits climbed 11.6 percent from August to an annual rate of 894,000 units. That’s an improvement of 45.1 percent from September 2011. Permits for multifamily homes increased by 20.3 percent in September to an annual rate of 323,000. Single-family permits were up 6.7 percent to an annual rate of 545,000.

Housing starts, too, were up 15 percent from August to a seasonally adjusted annual rate of 872,000 and up 34.8 percent from September 2011’s rate of 647,000. That breaks down to an 11 percent increase in single-family housing starts to a rate of 603,000, up 11 percent from August.

The Northeast was the only region that saw a decrease in starts, falling 5.1 percent.

Why is housing showing signs of a revival when the rest of the economy has slowed?

Economist Patrick Newport of IHS Global Insight says it’s a sign that demand for new homes has been pent up and is finally showing signs of release.

“It’s called population growth,” Newport explains. “Every year the U.S. population increases by about 3 million and the number of households increases by 1.1 million to 1.3 million. New homes have to be built to meet demand from this segment.”

Teresa Burney is a senior editor for BUILDER magazine.