Hint: You've probably seen a few of them on Cops.

Yep, mobile home parks! Yesterday, Gilchrist & Rutter's Richard Close (snapped on the balcony of his Santa Monica office) told us he's doing lots of transactions—both as buy and hold 'em investments, and for developers buying and closing them to build retail or multifamily. One recent example: the Village Trailer Park in Santa Monica, to be redone with condos and apartments. Another client's buying one in Silicon Valley to convert into mixed use.

We Googled this view of the Village Trailer Park. (That's right, Google can see you.) As investments, mobile home parks offer low maintenance costs and little to no vacancy. Moving a mobile home can cost up to $12k, so when residents leave, they generally sell to someone else. And with few new parks being built and more demand than supply, cap rates on mobile home park sales are very low.

Richard just returned from visiting his daughter in Boulder. He says California has 4,800 mobile home parks, about 1,500 of them ripe for redevelopment. The opportunities tend to be in urban or beach areas, places with little land. (The Montage Laguna Beach hotel replaced a mobile home park.) Richard says the end of redevelopment agencies made it tough to assemble large parcels, so developers buy these parks for good locations.

Richard says a state law guarantees that park owners can close them as long as it's pursuant to a redevelopment plan approved by the city, and they have to pay residents a fair relocation fee. (One recent case cost $4,000 per household plus $7,000 to buy each home.) Cities often cooperate with the developer because they want to see something else there, he adds. It's also a good way for national developers to enter into the LA or the Bay Area, he says.