Construction is underway for One York Street, a 40-unit condominium apartment project in TriBeCa that is added six floors to an existing 6-story mid-19th Century warehouse.

The development has been designed by Enrique Norten and is a project of Jani Real Estate of which Stanley Perlman is a principal.

Occupancy is expected in early 2007.

The full-block development is bounded by St. John's Place, Laight Street and the Avenue of the Americas.

The lower base of the building will be reclad but will retain much of its existing architectural style while the addition will be largely glass and slightly angled at its center where its facade will extend to the street. Part of the east side of the existing building is windowless because the building was reduced in size when the Sixth Avenue subway was built in 1927.

Norten, whose firm, TEN Arquitectos, is based in Mexico City and has an office here, is the architect of two other major projects now in planning that are likely to become quite sensational and important: Harlem Park, a 380-ft.-high, mixed-use project with an undulating facade on 125th Street and Park Avenue, and a new Brooklyn Public Library for the Visual and Performing Arts.

The Museum of the City of New York on Fifth Avenue at 103rd Street held a recent exhibition on these three Norten projects.

There will be 25 apartments in the older building and 15 in the new one that is setback from the lower one and has several balconies.

The fourth floor willo have a swimming pool and gym and one of the penthouses will have its own outdoor pool.

Residents can buy parking spaces in the building's automated parking garage where they park the car, swipe a card and the car is automatically taken to one of 47 parking spaces and later retrieved with another swipe of the card.

Prices are expected to range from about $1 million for a one-bedroom apartment to $2.4 million for a two-bedroom, two-and-a-half bath apartment with about 1,820 square feet to about $15 million for the double-height penthouse.