Named for its curved frontage, The Smile at East 126th Street contains a nursing school at ground level and 223 residential apartments above.
A chequerboard facade alternates between blackened stainless-steel panels and full-height glazed windows for the apartments.
On the rooftop, hot tubs, a swimming pool, candy-coloured loungers and lawns have views over the city.
The curving side of the T-shaped building is stepped back from the street and slopes inwards as it rises to maximise daylight for the interiors.
To the south, the building cantilevers over the existing buildings on 125th Street. Viewed from above, the building bends upwards like a drawing of a smile.
"The facade of The Smile drapes gently between the building's two neighbours and leans inward to allow sunlight and air to reach the street, thus fulfilling the century-old set-back requirements in a new way," said BIG founder Bjarke Ingels.
"Like a good neighbour, it fits into the existing neighbourhood, feeding from the community's energy to add new sparks to the community of East Harlem."
Colourful concrete entryways are designed to echo the bright hues used in the multi-storey artist's murals that adorn the buildings of East Harlem, depicting historic figures and sharing political messages.
One-third of apartments of The Smile, which occupies a historically black neighbourhood, will be reserved as affordable housing.
Steel panels for the facade were manufactured in Germany using a combination of mechanical and chemical finishing to create a durable surface.
"The Smile's facade takes inspiration from the textured surface of the moon, and blends with the black and red brick of the existing buildings in the neighbourhood," said BIG.
Inside, the interiors continue to nod to Harlem's history, with colourful herringbone tiles peppering the floor and a wall of mailboxes behind the reception desk.
"Residents are immersed in an explosion of reds, blues, greens, and yellows, inspired by Harlem's Puerto Rican and Caribbean culture and history," said BIG.
For the apartment interiors, those on the north side of The Smile are decorated in an industrial style with exposed concrete. To the south, the apartments feature exposed steel trusses and kitchen cabinets made from Italian steel.
Amenities for residents include a gym, spa and sauna, and access to a co-working space that overlooks a six-storey gallery in the building.
A communal lounge includes a kitchen and pantry for events and cooking classes.
BIG was founded by Bjarke Ingels. Recent projects by the practice include a design for a base on the Moon for NASA and a Copenhagen power plant with a dry ski slope down the roof.
Photography is by Pernille and Thomas Loof.
Client: Blumenfeld Development Group
Collaborators: ZDG, Thornton Tomasetti, Cosentini Associates, Milrose Consultants, Eckersley O'Callaghan, Langan, Van Deusen Associates, Aquatectonic Lothrop Associates LLP, Steven Winter Associates, Jaffe Holden, Robert Schwartz and Associates, Fox Rothschild, Lerch Bates
Partners-in-charge: Bjarke Ingels, Thomas Christoffersen, Beat Schenk, Kai-Uwe Bergmann
Project leaders: Michelle Stromsta, Jennifer Ng, Lucio Santos, Elena Bresciani, Everald Colas
Project leader, Interiors: Francesca Portesine, Jennifer Ng, Rita Sio, Jose Jimenez
Team: Adrien Mans, Agne Rapkeviciute, Annette Miller, Ava Nourbaran, Ben Caldwell, Benjamin DiNapoli, Daniele Pronesti, Deborah Campbell, Douglass Alligood, Eva Maria Mikkelsen, Gabriel Hernandez Solano, Iannis Kandyliaris, Jan Leenknegt, Jennifer Phan, Jennifer Wood, Jeremy Babel, Jialin Yuan, John Kim, Julie Kaufman, Julien Beauchamp-Roy, Kurt Nieminen, Lina Bondarenko, Mark Rakhmanov, Meli Harvey, Quentin Stanton, Sarah Habib, Shu Zhao, Taylor Fulton, Terrence Chew, Terry Lallak, Valentina Mele, Wells Barber, Wojciech Swarowski, Yaziel Juarbe, Yoanna Shivarova