YOU'VE HEARD it before. Everything old is new again.

Well, they don't call them truisms for nothing.

Developers are putting a new twist on the traditional storefront in the Chinatown area where several new condo projects are offering retail condos on the ground level below residential condo units. The proximity is attracting buyers who want to live above their businesses. It's almost - but not quite - a re-creation of the traditional neighborhood storefront where the owners' living quarters were just up the stairs.

In densely populated Chinatown, where space of any kind is at a premium, the combo is a powerful lure, says Robert Zuritsky, president of Parkway Corp. Parkway, who most of us know as the city's premier parking-lot owner, is building The Pearl Condominiums, a mixed-use project at 8th and Race streets, in partnership with Chinatown real estate broker Julie Wong.

The six-story building includes 90 residential units above 10 first-floor retail spaces. All of the retail condos and about 75 of the residential units have been sold, mostly to Asian buyers.

Wong said several business owners bought both residential and retail units, giving the owners a short elevator commute.

The nationwide real-estate slump appears to have skipped Philadelphia's Chinatown, where more than 10,000 people are jammed into the blocks between Arch and Vine streets, from 8th to 11th streets. Wong says the $200 million project is several months from completion, but already 87 percent of the units have been sold.

Wong credits the price, which is a bargain compared to other new condos in Center City and about one-third to half below the cost of condos in New York City. That has attracted a number of Asian-Americans who can no longer afford skyrocketing prices in the Big Apple.

The rise in population has pushed Chinatown's borders north to Spring Garden Street and beyond, where two new mixed-use townhouse projects are setting their sights on the Asian-American market.

The success of The Pearl has prompted developer Sam Sherman to consider adding residential-over-retail condos to his Spring Arts Point development at 9th and Wallace streets. He hopes to capture some spillover from the Chinatown market. Sherman wants to build and sell the retail and residential spaces as a single four-story unit with a first-floor commercial space topped by a three-story townhouse. That's similar to what buyers will be offered at Lucky Garden, a 25-unit complex under construction at Ridge Avenue and Buttonwood Street.

John Chin, executive director of the Chinatown Development Corp., views the proliferation of luxury condos with some dismay.

"We are concerned about gentrification and high-priced housing pushing out lower income people," Chin said.

"For Chinatown, where the majority of the population is lower income, that's not a good thing."

Chin said his non-profit community organization is trying to figure out ways to encourage mixed-income development.

He believes the city should be more aggressive in pushing developers - especially those who purchase land from the city - to include an affordable component in their projects.

For now, there are no affordable housing projects on the drawing board for Chinatown.

Instead, there are plans for a luxury W Hotel, another Parkway project, at 12th and Arch streets.

And Wong says she is seeking partners for a mixed-use condo development on a one-acre lot at 11th and Vine.

Unlike Chin, Center City District chief Paul Levy is happy to see what he calls "positive diversification."

"If you look at Chinatown over the last decade, there are two types of diversification going on," Levy says.

"You see a lot more non-Chinese Asian businesses opening, and you see a lot more financial institutions and travel agencies . . . a lot more than just restaurants."

Bringing in more folks with money - no matter their ethnic background - will make Chinatown a much healthier and diversified community. *