Manhattan's long-neglected high line has been the subject of much buzz in recent years, as plans for its transformation from elevated urban blight to picturesque urban park have gotten under way. It is fitting that one section of the elevated rail line runs through West Chelsea, a commercial gallery district, because what better found-art piece is there than a reclaimed fragment of early 20th century infrastructure? And nestled against the tracks, at the corner of 23rd Street and 10th Avenue, a new urban sculpture is inching higher.
Designed by Los Angeles–based Neil M. Denari Architects, the HL23 condominium building will stand at 14 stories once completed, with an articulated form that belies the traditional box buildings around it. It is situated on a potentially awkward 40-foot-by-99-foot site, with a height limit of 165 feet. In what principal Neil Denari refers to as one of the most intriguing aspects of the project for the design team, the High Line crosses 5 feet past the line of the street wall and into the site.
To maximize square footage for the developer clients Alf Naman and Garrett Heher, as well as to push the design envelope, the design team concocted a reverse tapered structure, which widens once it rises past the train tracks. The east façade cantilevers out over the tracks; unified at the bottom and top floors, the façade splits into two side-by-side ribbons for the seven floors in between, one ribbon extending further out toward the High Line and the other inset closer to the building's core.
“The way the building responds and reacts generates a kind of vitality of form with the east façade,” says Denari. “There's where we had to negotiate formally where the building would get wider as it was going up. That reverse tapering was the only way to make the building viable.”
The top four floors of the building are most dramatically canted, with the top west and top east corners shifting slightly to the east to form a trapezoid. Motivated in part to preserve light and air for existing neighboring buildings, Denari describes these angles as an “imaginary diagonal skyplane” that would be the most direct point between the topmost and bottommost terrace, if he had stepped the building back in a traditional wedding cake–like fashion. “We asked if we could build that diagonal instead,” Denari notes, and the planning department said yes.
There are nine full-floor residences, one duplex penthouse, and one ground-floor maisonette. The building's articulated façade means that every floor plate is different, which poses a particular challenge for the interior architect, Thomas Juul-Hansen. (Juul-Hansen was brought onto the project by the developer, who thought that Juul-Hansen and Denari's styles would play well off of one another.)
The building shifts around a vertical core, making it impossible to create a consistent layout. This combined with the diagonal braces on the inside of the curtain wall made this “by far the most difficult coordination project we've been involved in,” says Juul-Hansen.
The interior designer managed to maintain basic organization from unit to unit, positioning all the units' master bedrooms on the north side of the building and living rooms on the east side. Because of the site positioning, views from the east, north, and south will remain in perpetuity—a rarity in New York.
The overall goal for the interior was high-end simplicity, offering buyers a blank canvas to make their own. Materials such as stone slab counters and Miele appliances ensure that no one will have to do a gut renovation of kitchens or bathrooms when they move in. Juul-Hansen notes that he “stayed with something fairly clean, fairly simple. Between the shape of the building and the views, that will become the theater.”