In the middle of the last decade, Alchemy Properties built a condominium building at 50 West 15th Street. The architect on the project, incidentally, was FXFOWLE. In the process of clearing the building with the community, the developer got to know some of the folks in the administration of Xavier High School, one of New York City’s top Jesuit educational institutions. The school’s campus, which is across the street from the condo, includes some nice Italianate style buildings, including a church that faces 16th Street designed by Patrick Keely. In addition to admiring the architecture, the people at Alchemy discovered that Xavier had unused development rights in the air above its mostly five-story complex and that it wanted to expand. Shortly thereafter, the 75-foot-wide lot at 35 West 15th Street opened up and Alchemy made a deal with the school to build it a new facility in exchange for permission to put high-end residences on top. The result of this only-in-New-York paring is 35XV.
Designed by FXFOWLE, the building expresses its twinned program with two distinctive, but related, architectural treatments that reflect the realm of the street and that of the sky. The first six floors, which house 38,000 square feet of space for the school, including a double-height gym, as well as the residential lobby, are clad with white Mount Airy granite. This light, bright material presents a modern face while at the same time fitting into the 19th-century streetscape. The vast majority of the granite has a thermal finish, giving it a rough texture but soft appearance, since it diffusely reflects light. The exception is within the window wells and doorway, where the granite has a high honed finish. The architectural notion is that this rugged base has been carved away with a very sharp, smooth knife.
The seventh floor is a transition zone to the realm of the sky. It contains the residential amenities and a sizeable terrace on a 20-foot setback. Floors eight and up (there are 25 stories overall and one cellar level) are occupied by one-, two-, three-, and four-bedroom luxury units, 59 total. This tower portion of the building is angled to follow the sky exposure plane established by the neighborhood’s zoning laws. In order to maximize usable square footage, it hangs off the back of the lower section, supported by angled “flying buttress” style steel columns that tie back into the podium.
A skin of silver-painted aluminum and double-glazed, high-performance glass clads the residences. The vertical portions of the curtain wall are articulated to resemble shingles or fish scales, while the angled portions are flush. The windows from level to level are also staggered, much like courses of brick, with a pattern that repeats every three levels. This staggered fenestration is also present in the windows of the lower part of the building, creating a common vocabulary that ties the two otherwise disparate sections together.
The tower is separated visually into two volumes—the angled street volume and the predominantly vertical rear volume—by a strip of the metal panels, thus breaking down the mass of the structure. The east face is completely covered in the metal panels, which conceal the building’s parti wall. The crown of the tower comes to a point, also clad with the metal panels, opening a dialogue with the Keely church below.
Structurally the building is also divided. The lower section is framed with structural steel, while the upper portion is cast-in-place concrete. The seventh floor features four, full-height structural steel transfer trusses. The concrete tower is fairly typical, except for the 12th floor, which is post-tensioned to handle the considerable forward thrust generated by the building’s sloped form.
