The doom and gloom that has settled over many of the nation’s residential housing markets hasn’t put everyone in the dumps.

With thousands of people forced into the rental market by a wave of foreclosures, and thousands more prevented from climbing out of it by tightening lending standards, prospects are looking up for those who handle rental housing.

“For property management professionals, it happens to be good right now,” said Gail Phillips, executive director of the Chesapeake, Va.-based National Association of Residential Property Managers, a trade association that includes more than 2,800 members.

Still, not all is bright in rental markets.

In some markets, the flow of new renters has been overwhelmed by an even bigger tide of unsold homes, keeping downward pressure on rents and lengthening turnaround times. And in markets hit hard by foreclosures, property managers and their tenants are working new legal language into their leases to protect themselves from the consequences of overstretched property owners who stop paying their mortgages.

There’s also the question of what to do with people who were driven into the rental market by foreclosure on their own homes, said Sylvia Hill, the broker/owner of H.M.S. Development, Inc., a company that manages properties in Monterey and San Jose, Calif. Should that be held against them on a credit check, or not?

In many cases, Hill said, probably not. “These people have not lost their jobs,” she said. “It’s not like they can’t afford a payment. They just can’t afford the payment at the level it was at.”

About 2.8 percent of the total housing stock in the 75 largest U.S. cities stood vacant and for sale in 2007, according to the U.S. Census Bureau’s survey of housing markets – about 75 percent higher than the average vacancy rate dating to 1986. Most of the empty inventory built up in the later years of the housing boom, rising from 1.7 percent in 2004, or slightly above the historical norm, to the highest number in two decades by 2007.

Rental vacancies, meanwhile, dropped a bit, from 10.2 percent in 2004 to 9.8 percent in 2007. That number was still about 25 percent higher than the 21-year average, according to the Census Bureau. A quick look at some of the country’s local rental markets:

Orlando

Orlando’s market has been one of the hardest hit by the housing bust, and its heavy inventory of unsold homes is affecting the rental business as well. About 7.4 percent of the metropolitan region’s housing inventory stood empty in 2007, according to the Census Bureau, and rental vacancy rates hit 11.3 percent.

Diana Blake, a broker with Classic 1 Realty in Orlando and a past president of the property management association’s Orlando/Central Florida chapter, is advising some clients to cut their rents just to keep good tenants from leaving.

“The rental amounts are decreasing because we’re inundated with rentals,” Blake said.

Las Vegas

A couple of years ago, 90 percent of the prospective renters who trickled into RE/MAX Advantage agent Sandra Thomas’s office came directly to her, enticed by a sign on a house or an apartment. Today, Thomas said, real estate agents bring in about half of her new renters. Some of the clients couldn’t qualify for a mortgage; some agents are hungry for the $200 finders’ fee.

As in Orlando, thousands of new rental homes are on the market, Thomas said, but rents remain flat. About 4.9 percent of Las Vegas housing stock stood empty in 2007, according to the Census Bureau. The rental vacancy rate stood at 10.9 percent.

Central California

Rents in Central California’s coastal cities went into a steep decline during the peak of the residential housing boom as renters moved into homeownership, said San Jose-based Hill. But rental rates gained traction and slowly moved up as the housing bubble began to break a couple of years ago, Hill said. Now, rents are leveling off again.

At 3.8 percent, the San Jose metropolitan area’s rental vacancy rates remain far below the national average, according to the Census Bureau, and the proportion of vacant homes for sale, 0.8 percent, is also well below average.