The residential building at 520 West 28th Street in New York City, also known as the Zaha Hadid Building, was her only residential building in New York and one of her last projects before her passing. The duplex penthouse suite features a custom spiral staircase spanning three stories with a handrailing designed as a monolithic ribbon-like form. With a preliminary design provided by the client, ASTOUND initiated the project with a 3D scan of the suite which the digital fabrication department received and incorporated into the architect’s rough model.