West side story.

In an unusual move, Rockrose Development Corporation intends to build atop its 220,000 s/f commercial property at 660 12th Ave., between West 48th and 49th Streets.

Rockrose purchased the land in 1998, planning to build New York's first ground-up telco hotel at the site, with a Federal Express distribution center as the anchor tenant at the base of the building.

The developer then changed course when the telecommunications market abruptly collapsed. Since a lease had been signed with FedEx, Rockrose completed the basement and first two floors as a distribution center, building the infrastructure for future development of the upper floors.

Rockrose, which owns 315,000 rentable s/f of air rights there (more, if there is a mechanical space need), now plans to enlarge the structure once it secures a tenant for the additional space atop the building. The height of the building is not limited, except by the sky exposure plan. Two full 90,000 s/f floors and two additional floors of 66,000 rentable s/f can be added if the tenant desires large floorplates.

The building offers a rare opportunity for a tenant seeking large, build-to-suit space in midtown west, possibly cutting construction time by 50%, notes Patricia Dunphy, vice president of Rockrose.

"Since the building was originally intended as a telco hotel, it has very high-caliber structural and technological features," says Ms. Dunphy.

"In addition, the enormous floor plates and oversized elevators would make it a perfect location for a manufacturing company, warehouse or storage facility. We're open to all suggestions."

Rockrose has already spoken to several prospective tenants, including a tennis club operator, various city agencies, a television studio, and a night club, among others.

Many prospective tenants are also interested in the building's potential roof space, says Ms. Dunphy.

"Will it be a hydroponic farm or tennis courts?" she asks. "We are keeping an open mind. The sky's the limit."