Two things are set to happen at midnight Friday that could cause new problems for the real estate market.

First, barring last-minute action by Congress, the National Flood Insurance Program will lapse. The last time that happened, just over a year ago, it delayed an estimated 47,000 real estate closings across the country and about 2,800 locally, according to state and regional real estate associations.

"Having this program expire, as it has (previously), creates delays in transactions," said Nick Kremydas, chief executive of South Carolina Realtors trade group. "With many mortgages, particularly for coastal properties, the underwriters require flood insurance."

If the program were to lapse, for what would be the sixth time in three years. Those who have flood insurance would continue to be insured, but anyone who wants or needs a policy would be unable to obtain one.

The House and Senate have passed different plans to extend the program, and would have to reconcile their differences. Kremydas is hopeful that at least a temporary extension will be approved this week.

The second thing that will happen Friday, also barring legislative action, is the expiration of a federal stimulus provision that raised the limits for Federal Housing Administration loans. The provision, approved in 2008 during the Bush administration and extended several times, was meant to expand mortgage opportunities at time when private lending was becoming more restrictive.

In Berkeley, Charleston and Dorchester counties, the maximum FHA loan would drop from $335,000 on Friday to $302,450 starting Saturday.

"You're talking about taking away 10 percent of purchasing power from qualified buyers," said Ryan Castle, government affairs director for the Charleston Trident Association of Realtors. "Our position is that (the higher limits) should be made permanent."

The expiration of the stimulus- related loan limits also will reduce the maximum loan size for Fannie Mae and Freddie Mac loans in high-cost areas, but not in South Carolina.

"When you lessen the availability of mortgage credit -- reducing liquidity in this market is just another thing hurting the recovery that we're trying to see in real estate and in the rest of the economy," Kremydas said. "There may be time to reduce these limits, but what we're asking is, not right now."