Urban Umbrella in Architect’s Newspaper

Two years after the NYC Department of Buildings and AIA New York launched the UrbanSHED competition to find a new sidewalk shed design that would beautify city streets, a prototype of the winning proposal has been unveiled. Called Urban Umbrella, the shed structure was developed by competition winner Young-Hwan Choi with architect Andrés Cortés and engineer Sarrah Khan of New York-based Agencie Group. Brooklyn-based architecture and fabrication firm Caliper Studio was hired late last year to detail and build the much-anticipated design, which the DOB and architecture, construction, and real estate backers hope will eventually replace unsightly sidewalk scaffolding at many of the city’s construction sites.

Like the renderings that much of the city admired when the competition winner was announced, the structure unveiled at an event at Caliper’s studio on Wednesday has an umbrella-like shape free of the low cross bracing used on traditional sheds. But taking the design from rendering to reality was no simple matter. The project was a highly coordinated effort to meet city building codes and stay within budget (the Downtown Alliance is funding the prototype), all while keeping an eye on the larger goal of eventually creating a time- and cost-efficient manufactured system with the appeal of the original models.

“We wanted to work with Caliper because there’s an artisanal quality to the work that they do,” said Cortés. “We were to going to get a high level of intellectual feedback.”

Because Caliper specializes in parametric modeling and rhinoscripting as well as metal fabrication, the firm was confident it could translate Agencie’s 2- and 3-D models into a working fabrication model that would allow the team to predict every cost. “Every single part was evaluated for cost,” said Caliper principal Jonathan Taylor. “Our model could tell us quantities and total weights.” Ultimately, Agencie submitted more than 450 pages of calculations for approval by the DOB.

Though the prototype will likely undergo some tweaks, the design works: The roughly 7-by-12-by-12-foot shed unveiled this week contains hundreds of pieces, but there are just eleven primary steel components. The team found it was more cost effective to source pieces from three machine shops rather than work with off-the-shelf parts. Pieces such as collars supporting the curved canopy were manufactured on a flatbed laser cutter, while a pipe laser cutter was used for the columns and a rolled-shape manufacturer sourced the curved members. The finished shed would be manufactured in two sizes, one for heavy-duty construction and one for lightweight applications, defined as buildings less than six stories.

To anyone who has ever stumbled over the wooden blocks used to jerry-rig traditional sidewalk sheds, the canopy’s leveling feet are a happy addition. The top part of the shoe is fitted with a narrow pipe that allows the shed to be raised 18 inches while the lower part can pivot 360 degrees. Tnemic epoxy paint coats the entire steel structure and unlike some other sprayed coatings can be touched up in the field with a paintbrush.

The team also delivered on the initial design’s hallmark—a clear roof that left some critics concerned about safety. Once it undergoes additional testing in the coming weeks, high-density polycarbonate will top the umbrella structure. “It’s bringing in 21st-century material technology to something that hasn’t been updated for 40 years,” said Cortés. The non-combustible plastic can withstand more than 300 pounds per square foot—a number derived from the force of a brick falling 300 feet. “Our shop floor is rated at 250 pounds per square foot and we drive our forklift around on it,” said Taylor by way of example. UV-stabilized film adhesives would also allow artwork or branding messages to be applied to the roof. At night, cutting-edge LED SMD (surface mount device) technology from a Korea-based LG affiliate will illuminate the shed, vastly decreasing the amount of electrical conduit, not to mention voltage consumption, at each shed. Several high-profile building sites in Lower Manhattan are still being considered for the prototype’s first official installation in the coming months, but by all accounts the general public won’t be kept in the dark much longer.

Stair den side I
Photo by Ty Cole.
Architectural design Richard Perry ArchitectPhotography by MYRIAM BABINDoor Detailing and Fabrication by Caliper Studio