Nearly two years after the recession ended, the pace of construction is inching along at less than half the level considered healthy. Single-family home building, the bulk of the market, has dropped 11 percent in that time.

Builders are struggling to compete with waves of foreclosures that have forced down prices for previously occupied homes. The weakness is weighing on the economy: Though new homes represent a small portion of overall sales, they have an outsized effect on jobs.

The Commerce Department said Tuesday that new-home construction plummeted in April to a seasonally adjusted rate of 523,000 homes per year. A major drop in volatile apartment building pulled down the monthly figures. And strong tornadoes and flooding also disrupted construction projects throughout the South.

Still, through the first four months of this year, the pace of new-home construction is barely ahead of 2009's - the worst year on records dating back a half-century.

"There are very few signs of recovery in residential construction," said Celia Chen, senior director at Moody's Analytics. "Absent evidence of stronger demand for housing, homebuilders will remain reticent to put up new homes."

The April drop in new-home construction was largely because apartment and condominium building plunged more than 28 percent. Single-family home construction, which makes up roughly 80 percent of the market, fell about 5 percent.

Building permits, a gauge of future construction, fell 4 percent.

High unemployment and tighter lending standards have greatly reduced the number of potential buyers who could qualify for a mortgage. And those who are eligible have more incentive to buy a previously occupied home.

The median price of a new home was about 34 percent higher in March than the median price for a re-sale. That's more than twice the markup in healthy housing markets.