Top: Exterior view, from Grand Avenue, of The Broad under construction. Bottom: Rendering of the exterior of The Broad from 2nd Street and Grand Avenue.
Carolina A. Miranda (top); The Broad and Diller Scofidio + Renfro (bottom) Top: Exterior view, from Grand Avenue, of The Broad under construction. Bottom: Rendering of the exterior of The Broad from 2nd Street and Grand Avenue.

Elizabeth Diller says that giving a tour of a building while it is still under construction feels very strange. "Architects don't often do tours in the middle of construction processes because you just feel so incredibly vulnerable," she says. "You have to explain what's not there—what's invisible."

Yet there is plenty that is visible to The Broad, the contemporary art museum that her firm—Diller Scofidio + Renfro—has designed for construction magnate and arts patron Eli Broad in Los Angeles. At street level, a gently undulating biomorphic room greets visitors in what will one day be the lobby. On the second floor, the walls that will surround the Broad's extensive archive have already materialized. And, on the top floor, a latticed web of pre-cast skylights—looking like a taut fishnet stocking—hangs over an acre of gallery space.

The Broad is not scheduled to open until sometime in late 2014, so the tour Diller gave was indeed on the early side. But Eli Broad is not the sort of architectural client who is going to wait for the paint to dry—or the skin to be completed—before showing off a building. So, on Tuesday, a group of journalists all donned hard hats to poke around the rebar and the purple "DANGER" tape for a peek at L.A.'s newest cultural destination.

Elizabeth Diller walks journalists through the second floor of the “vault” -- past a space that will be used as a public lecture room.
Credit: Carolina A. Miranda

Elizabeth Diller walks journalists through the second floor of the “vault” -- past a space that will be used as a public lecture room.

During his opening remarks, Broad acknowledged his reputation for moving quickly: "Those of you who know me know I'm not a very patient person. When it comes to projects, I want to move on." And Diller herself joked about his reputation for impetuousness. "When we won this, we felt it was a mixed blessing," she said. "We were very nervous about getting involved with Eli. We thought, 'Are we going to get fired in a couple of months?' But I have to say, the process has been great. Eli has been involved—very, very involved—in a kind of great way."

Certainly, the architectural program for The Broad is as difficult as the client. The $140-million building will not only house a museum, it will contain a storage facility—somewhat contradictory functions. Diller tackled this with an approach she dubbed "the veil and the vault." The building's lower two stories comprise the vault: a boxy, cantilevered structure made from 36 million pounds of concrete that will house offices, storage and archives, with a few public spaces woven in between.

On top of the vault resides the principal exhibition area: 35,000 square feet of column-free, light-saturated gallery space that can be configured in countless ways. To get here, visitors will ride an escalator that travels from the lobby in a tube that punctures the dense concrete core of the vault. If the early construction is any indication, this will be one of the best escalator trips in all of Southern California—a retro-futuristic people-mover that channels the old Disney science ride, "Adventure Thru Inner Space."

Third-floor gallery entrance with escalator, circular glass elevator and stairwell.
Credit: The Broad and Diller Scofidio + Renfro

Third-floor gallery entrance with escalator, circular glass elevator and stairwell.

A view of the 35,000 sq ft column-free gallery on the top floor.
Credit: Carolina A. Miranda

A view of the 35,000 sq ft column-free gallery on the top floor.

Wrapping the vault, along with the gallery that sits on top, is the so-called "veil," an intricate honeycomb screen made from fiberglass reinforced concrete panels (GFRC) held up by 650 tons of steel. During the day, this screen admits diffused daylight into the building. At night, it will give off a soft glow. The veil, Diller says, has been the most difficult aspect of the building to produce, designed in a CATIA program and requiring dozens of specialized molds to fabricate. "The level of complexity—you're not going to find a lot of fabricators that are going to want to jump into that," she explains. "And that could do it beautifully—it's being executed in a beautiful, beautiful way." (It is being built by MATT Construction, with Gensler serving as executive architects—both L.A.-area firms.)

Third-floor gallery entrance with escalator, circular glass elevator and stairwell.
Credit: Carolina A. Miranda

Third-floor gallery entrance with escalator, circular glass elevator and stairwell.

Lobby view from the north entrance with interior view of the glazing and veil.
Credit: The Broad and Diller Scofidio + Renfro

Lobby view from the north entrance with interior view of the glazing and veil.

With construction still underway, it's too early to tell how all the pieces might fit on the inside. On the outside, the building is certain to cut a dashing profile. But it nonetheless faces challenges, though these have more to do with expectation than design. The Broad is part of its patron's desire to revitalize Grand Avenue, the hilltop thoroughfare where the museum is located and a bizarre urban tapestry of bland corporate towers, public-private spaces that look like they were designed by bankers, and California design icons like Frank Gehry's (FAIA) Walt Disney Concert Hall, Welton Becket's (FAIA) Music Center and the cathedral by Rafael Moneo, Hon. AIA.

As other parts of downtown L.A. have revived, boasting plenty of street life, Grand Avenue remains a dead zone. "Every city needs a vibrant center," Broad said on Tuesday. "It was clear to me 50 years ago when we came here that Los Angeles was missing a vibrant center." How The Broad will help build that center is somewhat unclear. (Plans for an adjacent public plaza have yet to be sorted out.) What is certain is that Grand Avenue is a neighborhood riddled with block-sized cultural monuments. With his museum, Broad has added yet another.