Sales of new single-family homes declined 14.5 percent to a seasonally adjusted 384,000-unit annual rate in March, the National Association of Home Builders said.

Citing U.S. government data, the NAHB said sales fell 21.5 percent in the Midwest, 14.4 percent in the South and 16.7 percent in the Western U.S. Sales increased 12.5 percent in the Northeast.

"We keep hearing from our members that tight credit conditions are preventing many first-time buyers and younger families from being able to buy a home," said NAHB Chairman Kevin Kelly, a builder and developer from Wilmington, Del. "Congress must outline a clear policy on housing finance so that qualified buyers can get home loans. Otherwise, this continued uncertainty could threaten the housing recovery and overall economy."

David Crowe, the association’s chief economist, said banks are still excluding many credit-worthy would-be homeowners.

"Overly stringent underwriting standards for mortgages have had a detrimental effect on modest-priced markets and have hit first-time home buyers particularly hard," Crowe said. "As a result, most of the sales are coming from a smaller pool of buyers who have a more established credit history, are more likely to finance with higher cash downpayments and are purchasing higher-priced homes."