The $140-million, giant honeycomb-shaped Broad museum in Downtown Los Angeles inched closer to completion last week with the removal of the final scaffolding from the exterior facade, which finally revealed to the public the structure's signature "veil" design feature that wraps around the building.

The exterior veil is a structural exoskeleton comprised of 2,500 fiberglass reinforced concrete panels and 650 tons of steel that drape over The Broad and appear to lift up at the south and north corners to define two street-level entrances. At the center of the Grand Avenue side of the veil is the architectural feature known as "the oculus" - an intense indentation or dimple of the veil into the building. 

The project was designed by New York City-based Diller Scofidio + Renfro (DS+R), with the LA office of Gensler serving as executive architect. The building sits beside other downtown cultural icons on Grand Avenue such as the Walt Disney Concert Hall, which museum founder Eli Broad says helped influenced design. "We wanted something that would not clash with the Walt Disney Concert Hall, but we didn't want it to be anonymous either," said Broad last year.

When complete this fall, the museum will house nearly 2,000 works of contemporary art in The Broad Art Foundation and Eli and Edythe Broad's personal collection, which are among the most prominent holdings of postwar and contemporary art worldwide.  DS+R's innovative "veil-and-vault" design concept for the 120,000-sq-ft museum includes two floors and more than 50,000-sq-ft of public gallery space and a central "vault" to house the collections and lending library. 

Because of its asymmetrical shape the structure has been very challenging to construct. To make it all come together, the project's general contractor, Santa Fe Springs, CA-based MATT Construction, had to extensively employ a 3D modeling tool called Digital Project, which was developed by Gehry Technologies.

Roger Fricke, MATT's senior vice president of preconstruction, told me last year that the reason for using DP is the complicated nature of the shapes and the geometry of the building. "It is the most robust modeling software that we know of right now," he said.

The three-story building consists of a structural concrete core with window openings surrounded by a honeycomb-like "veil" wrapper. The veil is made of 2,500 fiberglass-reinforced concrete panels with more than 400 different trapezoidal shapes. The panels are attached to a 650-ton structural steel "net" backing. The net is attached to the concrete structural shear wall of the building at two points, on 2nd Street and on GTK Way.

Loads from the veil come down onto a 32-ton, 57-ft-long touchdown beam girder, which is shaped like a Viking ship. The bottom of the girder is embedded 5 ft below the sidewalk in a bathtub-shaped steel plate, measuring approximately 5 ft wide, 10 ft long and 5 ft deep. The girder is secured to the plate with 56 anchor bolts.

The project, which broke ground in May 2012, sits atop three levels of underground parking that contains 366 spaces in a total of 155,000 sq ft.