Domus, the eight-story, $71-million luxury apartment complex located on 34th and Chestnut streets, is up for sale - barely a year after its completion in the fall of 2007.

Domus was intended to be built and then put on the market shortly after, according to a spokeswoman for the building's developer.

With 290 apartments and 23,000 feet of retail space, the building has amenities such as a heated outdoor pool, private screening room, 24-hour concierge and WiFi internet cafe. Rent is between $2,200 and $3,200 monthly.

Still, 20 percent of the building remains unleased. Some students blame the empty apartments on the steep rent and the building's policy against leasing to anyone under 21 years old. Other Philadelphia residents consider the building's distance from downtown as a factor.

Cynthia Birdwell, a spokeswoman for Domus' developer, Hanover Co., said a lack of revenue was not behind the complex being up for sale.

"It's our business model to build a project and put it on the market," Birdwell said.

Birdwell also defended the company's decision not to lease to anyone under 21.

"We chose to maintain the integrity of the project," she said. "We have everything from young professionals to graduate students and that's a plus."

She added that there is no asking price for the property and that, in today's market, it would be difficult to predict what the market price would be.

"We will not know until the bids come in," she said.

About half of those who reside in the complex are in some way affiliated with the University, either as students or employees.

Paul Sehnert, Penn's director of real estate development, said the sale should not come as a shock to anyone.

"It's common for developers to build and then sell to an institutional investor, and sometimes, it's part of the typical business plan." Sehnert said. "As the developer takes risks in financing and constructing a property, they operate for a certain period of time and then decide to sell and invest the proceeds into new projects."

Birdwell added, "It was always the ventures' intent to build Domus and sell it to an institutional investor."

Sehnert said he believes the complex will maintain its position as a market rate rental property.

"It's difficult to predict what the market price will be, even in the most buoyant of markets," Sehnert said. "Eventual pricing will reflect real world responses from institutional investors."