Nestled within one of Tribeca’s oldest cast-iron facades, the Stealth Building is a beautifully restored residential building. However, upon closer examination, this Lower Manhattan gem reveals many innovative restoration and renovation practices by the esteemed architecture firm WORKac.The Stealth Building is more than just a series of spacious loft residences; it is a testament to WORKac’s creative prowess and ability to meet challenging design requirements. In this article, we explore the unique features and challenges of the Stealth Building restoration project and how WORKac succeeded in creating a stunning residential space that respects the building’s historic past while embracing modern design and innovation.

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The Hidden Penthouse_©Laurian Ghinitoiu

Tribeca’s cast-iron History

Tribeca’s cast-iron buildings were constructed in the second half of the 19th century. New cast-iron technology allowed very short construction times and enabled large windows and vast open floorplans. The cast-iron façades were adorned with classical French and Italian motifs.

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Pre-restoration condition of the column capitals_©Michael Hansmeyer
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The Original Sketches_©Michael Hansmeyer

Originally constructed as factories and warehouses, they were in use until the 1960s, when stricter labour regulations and new zoning forced factories to shut down. In the aftermath, artists began to move into the buildings, drawn to the large interior spaces and affordable rents. Eventually, galleries and retail establishments followed suit, leading to a gentrification of the area.

While many of these cast-iron buildings have survived completely intact, others have suffered from the effects of time and weather. Significant parts of the façades have rusted away, leaving behind a shell of their former selves. To compound matters, many of these buildings have no remaining architectural drawings or photographs, making their restoration a significant challenge. However, their historical significance as emblematic of New York’s industrial past has made their preservation and restoration a priority for architects, developers, and city officials alike.]

The Stealth before

The Stealth Building of 1884, located at 62 Wooster Street in the SoHo neighbourhood of Manhattan, is one of the originally constructed five-story cast-iron commercial buildings and later expanded to six stories in 1899. During the 1920s, the building became home to garment factories and other commercial tenants. In the 1960s, artists and other creatives began to occupy the building as live/work spaces, drawn to its large loft-style interiors and affordable rents.

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The Stealth_©Bruce Damonte

Over the years, the building continued to attract artists and other creative types, with many using the space as studios and galleries. 

In 1970, the building was designated a New York City landmark, recognising its historical and architectural significance.

Despite its landmark status, the building fell into disrepair in the following decades. When it was purchased by a private developer in 2011, it was in dire need of restoration and modernisation. The developer commissioned the architecture firm WorkAC to restore and convert the building into a mixed-use space with luxury residential units and ground-floor retail.

Before its restoration, the building’s façade was deteriorating, and the interior was disrepair. The mechanical systems were outdated and inefficient, and the building lacked amenities such as an elevator. However, the building’s historic character and unique features remained intact, including its cast-iron façade and large interior spaces.

The Shadow

The Stealth Building’ comes from a hidden rooftop structure containing the development’s three-story penthouse.

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The Shadow_©Laurian Ghinitoiu

The Stealth Building is a unique example of blending contemporary architecture with historic preservation. The challenge was to comply with the city’s landmarks commission’s requirement that any rooftop addition be invisible while also being located on a prominent corner plot with a low, two-story structure across the street.

The architects used creative massing and three rooftop projections to overcome this challenge to mask the addition. The triangular pediment of the adjacent Carey Building, the circular pediment, and an abandoned elevator bulkhead at the top of the Stealth Building were utilised to create a “shadow” that informed the available area for the new structure. A result is a sculptural form that steps back from the street and is invisible from below while hidden from nearby buildings’ upper floors.

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Axonometric of the Roof_©WORKac
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Roof Evolution Diagram_©WORKac

WORKac’s innovative restoration and renovation practices created a spacious loft residence with a hidden penthouse while preserving the building’s historical significance and meeting the city’s strict guidelines for rooftop additions.

The Interiors

The Stealth Building features four luxury condominiums, including three floor-through apartments that span 1,650 square feet each. These units are complemented by a three-level, 3,400-square-foot penthouse that was created by adding a 1,750-square-foot addition to the top of the building. The lower simplex units include a unique design feature by WorkAC, which created freestanding volumes for kitchen, storage, and bathroom spaces, leaving additional living space above. This design takes advantage of the building’s impressive 13-foot ceilings. 

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The Penthouse_©Bruce Damonte
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The penthouse on the fifth floor combines the property’s sleeping quarters with a family room and entertaining and dining spaces under the new roof on the sixth floor. The roof contains a hidden rooftop structure that houses the penthouse, making it invisible from the street below. A secluded terrace behind the pediment offers stunning views of the Woolworth Building, while the former elevator bulkhead has been repurposed to house a hot tub. The architects have effectively blended historic preservation with contemporary design to create a unique living space that seamlessly blends the old and the new.

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Axonometric of the Penthouse_©WORKac

The interior design of the Stealth Building is a unique blend of nature-inspired elements and innovative urban living ideas. A “bonsai apartment” has been created in each apartment, positioned atop a volume containing bathrooms and storage space. This area is a “third space” between the sleeping and living areas and features a futon, seating areas, and a herb garden above the kitchen. Additionally, a fern garden connected to the master shower is watered by the steam that collects on its glass walls.

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The Interiors_©Bruce Damonte

A tessellated green wall was installed in the lobby, and generous planters were added to several floors. Balconies provide connections to the outdoors.

The Facade

The 1857 facade is completely restored. As the building’s Corinthian column capitols had been lost to history, WORKac collaborated with the artist Michael Hansmeyer to create new versions.

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The New Corinthian column_©Bruce Damonte

Hansmeyer developed a computer script that allowed the classically floral elements of the Corinthian order to “grow” fractally, resulting in a design that adheres to classical proportions yet is composed of new forms.

A total of 25 new Corinthian column capitals adorned with foliage motifs were added to the façade to replace the long-lost originals. The new capitals were cast not in iron but in malleable glass-fibre-reinforced concrete based on a CNC-cut foam model. 

Column Capital_©Bruce Damonte

This exemplifies the sophisticated layering of preservation and invention throughout the project.

Today, the Stealth Building is a beautifully restored mixed-use space with five luxury residential units and a ground-floor retail space. Its location in the heart of SoHo makes it a desirable destination for anyone looking to live or work in one of New York City’s most vibrant neighbourhoods.


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  • Jenna McKnight |10 November 2016 12 comments (2017) Workac adds jagged rooftop extension to historic Manhattan Building, Dezeen. Available at: (Accessed: April 1, 2023). 
  •  Rojas, C. (2016) The Stealth Building / WORKAC, ArchDaily. ArchDaily. Available at: (Accessed: April 2, 2023). 
  • Reade Street – Capitals   (2016) (no date) Michael Hansmeyer – Reade Street Capitals. Available at: (Accessed: April 2, 2023). 
  • designboom, philip stevens I. (2016) WORKAC’s stealth building in New York is topped with a hidden penthouse, designboom. Available at: (Accessed: April 2, 2023). 

Isha Ralhan is a 5th-year undergrad student pursuing a bachelor's degree in architecture. She likes learning about new things and traveling to new places. She enjoys photography as a hobby, reading books in her free time, and adores cats.