Robert Krier lives in a 6,000-square-foot dream home. For $600 a month.

Krier and his wife, Patricia, have found a sweet spot in the market. They take advantage of the glut of empty homes for sale. The couple are among a class of tenants known as ''caretakers," charged with keeping unsold properties in good shape and staged to impress potential buyers.

For $600 monthly rent, the Kriers live in a stone house in downtown Denver that has stood for more than a century. It boasts five fireplaces, four bedrooms and a wraparound wooden porch. ''It's real nice," says Krier, a 65-year-old semi-retired music teacher.

The Kriers are clients of Denver-based Caretakers of America, or COA. Other caretaker businesses dot the national landscape, although none are affiliated with the original in Denver, says founder Randy Bridge. He and entrepreneurs such as Tom Schmidt, who started Homes In Transition, or HIT, in Albuquerque, N.M., have been matching owners of vacant properties with flexible tenants since the savings and loan crisis of the late 1980s.

"We find credible, well-vetted tenants," says Schmidt. The background check includes immigration status, criminal history and credit standing. ''We don't place people randomly. We look at the furnishings they own and match these individuals to the various properties in the program."

HIT charges $680 a month in rent, regardless of the size of the 80 homes in its stable. ''Caretakers pay a screaming great rate to live in an excellent house," Schmidt says. COA's rents don't exceed $600 for its inventory of 60 homes that list for $350,000 to $600,000, Bridge says. HIT and COA make tenants pay utilities and any homeowner association fees. Tenants maintain landscaping, keep the house clean and handle minor repairs.

The Kriers got in the game seven years ago at the height of the housing market after the last of their seven children left the 3,000-square-foot home they shared. ''We were trying to downsize, and the house sold very quickly," Krier says. The couple is now on its 11th property. They stayed in one for 18 months; their shortest stint was 90 days.

Bridge says all sorts of people sign up to rent as caretakers. ''It's regular folks moving into the area, looking to get a feel for the market before buying," he says. ''It could be people with financial difficulties, looking to get back on their feet but who can't afford a place big enough for a family." Some caretakers have relocated for a short-term job. Others are having a house built but sold their previous home faster than expected, so they need to rent for a while.

Tenants must be ready to show seven days a week for about 10 hours starting around 9 a.m. ''These caretakers are living in a bit of a fishbowl," Schmidt says. Krier says showings average two a day when a property first lists, but the flow slows after a week or two. ''You have to have the place straightened up before you leave for work, the dishes done, the bathrooms neat," he says.

Tenants must be ready to move on 30 days' notice, although Schmidt says it often takes longer than a month to get from contract to closing. COA can boot its clients in 10 days, but Bridge says most caretakers get a month's notice.

"It's a pretty cool idea," says Tracy Highspencer, an agent with Century 21 Camco in Albuquerque, N.M. He's sold two homes that have had caretakers in them. ''A lot of times, a home will show better with furniture in it than when vacant." Home-staging firms have for years been selling services to furnish vacant properties using that theory.

Putting in tenants takes staging a step further, even adding more ''life" to a property, says Brian Sanchez, who listed his house with HIT in New Mexico after moving to the Washington, D.C., area for his job. ''There's inherent warmth when somebody is living in a home, and that comes across." His 3,150 square-foot home lists for $570,000, and he says it would rent for more than $3,000 a month. But the headaches of becoming a landlord made that option untenable for him.

Sanchez is typical of the homeowners who hire caretaker firms, worried that the property might fall into disrepair or get vandalized. HIT charges them $1,500, but knocks $500 off that for every 30 days the house doesn't sell. COA charges no fee to owners.

Even though the housing market has shown signs of recovery, HIT and COA say they will survive even another bubble. ''We've been around in good times and bad," Bridge says. That means opportunities for people like the Kriers to live in palatial homes for bungalow-sized rents will persist.

X...X...X

Mortgage rates inched down this week as anxious investors sought safe investments such as Treasury notes and mortgage bonds.

The 30-year fixed-rate mortgage fell 3 basis points to 3.61 percent. A basis point is one-hundredth of 1 percentage point.

The 15-year fixed-rate mortgage fell 4 basis points to 2.85 percent. The average rate for 30-year jumbo mortgages, or generally for those of more than $417,000, fell 5 basis points to 3.98 percent.

The 5/1 adjustable-rate mortgage fell 4 basis points to 2.66 percent. With a 5/1 ARM, the rate is fixed for five years and adjusted annually thereafter.

(Reach writer Jeremy Herron at editors@bankrate.com).

AP-WF-04-18-13 1857GMT