Bolstering its reputation for pioneering unique solutions to help developers build on challenging infill sites and meet increasing demand for urban housing, RKTB Architects has announced the completion of an innovative, new multifamily residence at One Sullivan Place in Brooklyn, New York. Featuring dramatically cantilevered upper stories that spread out beyond the narrow site and over the rooftops of neighboring buildings, the design captures breathtaking views of the nearby Brooklyn Botanic Garden and the Manhattan, New York, skyline for many of the new residents.

The design solution by RKTB represents the outcome of a close collaboration with developer group 1 Sullivan Residences LLC that aimed to maximize the buildable floor area for the small corner site by capitalizing on the air rights of neighboring buildings. The unique, 60,000-square-foot, mixed-income residence offers 52 senior, affordable and market-rate apartments. One Sullivan Place is also notable for being one of only a few projects developed under New York’s short-lived Privately Financed Affordable Senior Housing program.

Part of a larger under-built lot owned by the developer, the corner site in Crown Heights fronts just 40 feet along Washington Avenue and only 97 feet of Sullivan Place, according to Peter Bafitis, AIA, managing principal of RKTB, a firm long-known for its commitment to improving cities through social equity and design excellence.

“Our team aimed to reconcile the small site size with the considerable amount of developable floor area available to capitalize on,” Bafitis said. “Building straight upward would not have delivered the best ‘bang for the buck’ for our clients, especially on this prominent site with the Brooklyn Botanic Garden across the street and the potential for views of Brooklyn and Manhattan from above the tree line.”

Early on in the project, RKTB began exploring strategies for taking advantage of the fact that their client also owned an adjacent property: the fully occupied six-story apartment building at 1035 Washington Avenue. Because that building’s bulk height was already maximized due to its construction classification and area, talk turned to leveraging available air rights. The team ultimately arrived at the cantilever strategy that would theoretically allow them to build literally over and above the neighboring buildings, but the narrow building frontage posed a significant challenge.

“Working very closely with GACE Structural Engineers, we arrived at a solution – a two-story steel truss spanning 30 feet beyond the property lines, both north and east,” said Nelson Vega, AIA, associate principal with RKTB. “Occupying the ninth and 10th floors, the truss functions as a tabletop to support the 11th and 12th floors above.”

The architects incorporated large wraparound, floor-to-ceiling windows to animate the building’s corner and further enhance visibility, capturing panoramic city views that would help fetch competitive market rental rates – an essential component for making it possible to include affordable and senior rental units.

Since the 1970s, RKTB Architects has been synonymous with innovation in multifamily design and development in the New York Metro region and beyond. Other recent works include the Pope Francis Apartments at Loreto in Brooklyn and Phoenix Estates II in The Bronx, New York – both of which leveraged inclusion of senior units to increase developable floor area – and 1425 Fulton Street in Brooklyn, the design of which leveraged air rights (in an entirely different way from One Sullivan) to increase height and developable size on a tight site. RKTB is currently involved in efforts to identify solutions for converting vacant commercial space into affordable housing, drawing on decades of successful adaptive reuse work across typologies.

“Our firm has been doing this a long time, so we bring depth of knowledge to the table, especially with respect to navigating complex, labyrinthine zoning and building codes,” Bafitis said. “We’re honored and excited to have been a part of making One Sullivan Place such a successful development.”