This renovation and expansion in 2004 of a small, former industrial loft building into luxury residential condominiums is one of the most startling and spectacular projects of any size in the city in decades.

It is all the more exciting because it is tucked away in a mid-block location in what has become informally known as "Hudson Square," the former hub of Manhattan's commercial printing district, which sits alongside the Hudson River between TriBeCa and the village. It's not too far away from an architectural ancestor, the dramatically curved fa??ade of the Shaare Zedek Synagogue at 47 White Street that was designed in 1967 by William Breger.

Manhattan is forested to a very great extent with rectilinear structures with the obvious and rare exceptions of the upside-down cone of the Solomon R. Guggenheim Museum and the Flatiron Building, both on Fifth Avenue, at 88th and 23rd Streets, respectively.

The Austrian Cultural Building on East 53rd Street and the LVMH Building on East 57th Street, both between Fifth and Madison Avenues, are also important exceptions as they emphasis their angularity.

This building is perhaps the first to be completed in the city to manifest the sensuous complex and rippling geometries that were made famous by Frank O. Gehry s Guggenheim Museum in Bilbao, Spain. Gehry designed another titanium-clad, sail-like monumental structure for the Guggenheim Museum for a site along the East River south of the South Street Seaport but that plan was abandoned because of funding problems.

Unlike Gehry's shiny metallic fa??ades, this building's uses blue-tinted glass to cover its new portions and it cascades down from its setback upper floors, which extend over the 6-story,

older structure. The new glass tower is a full 11-stories high and features three lower floors of flat glass curtains, with the remaining "crinkled" stories featuring dramatic asymmetric curves.

The 23-unit development, which is known as The Greenwich Street Project, is located between Spring and Canal Street close to the Holland Tunnel. It is immediately south of another luxury condominium apartment project at 505 Greenwich Street on the southeast corner of Spring Street that also happened to be built at about the same time and also sports a sleek glass fa??ade. The handsome building at 505 Greenwich is taller and larger and rectilinear and looks more like a modern office building than an apartment house.

Winka Dubbeldam, the principal of Archi-Tectonics, is the architect and she is also an adjunct assistor professor of architecture at Columbia University.

This project has a multi-level fitness center with an endless pool, sauna and showers; "white-glove" storage; a wine cellar; a private landscaped garden; a media screening room and a duplex guest apartment.

Where the north side of the older structure meets the new construction are six small protruding white parapets, or small balconies, that serve as a "crease." These parapets conjure hooks or a zipper or an oceanliner lookout. This site, of course, is only a block or so away from the Hudson River. There is a four story glass penthouse unit in the modern tower that wraps around the original warehouse building, which features unobstructed river views.

It is remarkable that this project incorporated the existing fa??ade of the older building and one could argue that such a noble gesture in this case was not necessary as one wants more of the sensational glass "modern" fa??ade. Indeed, the glass fa??ade treatment here should probably have been used for the "new" Museum of Modern Art on West 53rd Street that is due to reopen in late 2004.

It is also interesting to note that the building to the south of this on the same block has been nicely renovated with some modern touches at the Canal Street corner and that another small building on the same block but on the other side of Greenwich Street has been remodeled with a very handsome multi-paned fenestration. As a result, this block is one of the most interesting in the city.