Foster + Partners–Designed Bloomberg London HQ Opens

As architectural terminology goes, “sustainable” is perhaps the least inspiring building descriptor of all. Despairingly mis- and over-used, it’s come to be the term clients roll out in briefs to fill space on paper. However, when Michael Bloomberg told an audience on Tuesday morning that his firm’s new London headquarters was the “most sustainable commercial building in the world,” there was a collective hunch that the term had some clout.

“For many companies our size, building a new headquarters would have meant opting for a glass skyscraper,” continued the former New York Mayor. He was standing on the headquarter’s sixth floor, a space that facilitates arguably one of the best views of St. Paul’s Cathedral, Christopher Wren’s masterpiece. And indeed the Foster + Partners–designed Bloomberg HQ is not a shiny glass skyscraper akin to the coterie of towers—including Foster’s “Gherkin”—that poke out behind St. Paul’s.

Instead, the ten-story building is clad predominantly in sandstone that was sourced from the U.K.’s Midlands and emulates the adjacent 144-year-old City of London Magistrates Court. “We could have gone higher in places, to 22 stories, but Bloomberg elected to keep the building at a continuous height,” said Michael Jones, a senior partner at Foster’s firm. Indeed, the project very nearly did reach such heights. More than a decade ago, Bloomberg commissioned Foster + Partners and French practice Atelier Jean Nouvel. Together they produced a project in 2006 that was comically lambasted as “Darth Vader’s helmet.” The project was ditched in 2009 and two years later Foster + Partners emerged as the lead architects with a new scheme.

Sitting on a 3.2-acre site, the building is still massive, with floor-to-ceiling heights reaching a minimum of 9.5 feet for office space. To ease its presence in a historical neighborhood already boasting iconic modern architectural splendor, notably James Stirling’s No.1 Poultry across the road, the architects made several incisions to deliver three public spaces and routes through the HQ. For example, an arcade reinstates a portion of Watling Street–once a Roman road–connecting Cannon Street station to Cheapside.

The Romans, it turns out, have made an even more emphatic return to the area as well. In 1954, excavation work being done on the site uncovered a temple to the god Mithras. The discovery caused a stir sixty years ago, with Winston Churchill’s cabinet raising the topic three times. The public was given two weeks to see the temple remains before they were relocated. Attendances were generally expected to be low, however, 35,000 queued to see Mithras’ shrine on the first day. Now Bloomberg has returned the temple to its original site. “The idea was to be very contextual, to do a building with a predominant feel of the area,” said Jones, and this approach is evidenced in the  “London Mithraeum,” where the temple will be on public display inside the Bloomberg HQ starting later this fall. Here, a selection of more Roman artifacts discovered from a dig in 2012 will be on show.

This classical context is mimicked in the hierarchy of the building’s frontage: there’s a clear top, middle and bottom, with a double-height base seemingly propping up the building. But that is where historical precedents end. To achieve its sustainability status, the building is decidedly modern (what more would you expect from a ‘high-tech’ architect?) and uses innovative methods for passive energy control.

Described by Norman Foster as the building’s “gills,” 250 bronze fins dominate the facade. These double as both shading and ventilation devices, bringing air into the building when the external temperature is just right. Another partner on the project, Kate Murphy, told Metropolis that full-scale 1:1 models of the facade were assembled in a Battersea warehouse to test the passive system. The mock-ups faced the rigors of anticipated climate change, being subjected to the “coldest of winters and the hottest of summers.”

The passive approach continues inside, too. A dazzling ceiling, which spans the majority of all floors, is comprised of what Foster calls “petals.” According to Jones, the design was inspired by the pressed metal ceilings of New York and contains an array of folded and polished aluminum panels that reflect light and attenuate sound. Some 2.5 million petals populate Bloomberg’s office, coming with 1.5 million LED lights. Behind the vast, tessellating array, copper coils filled with water serve to cool the HQ’s 4,000 inhabitants. “Without this ceiling, the whole passive system wouldn’t work,” stressed Jones.

For its green-fingered efforts, Foster + Partners was rewarded an “Outstanding” rating by BREEAM, the U.K. equivalent of LEED, scoring 98.5 percent on BREEAM’s rating system—the highest score ever awarded to date. It’s worth noting too that the office heavily discourages getting to work by car. Only five parking spaces—the statutory minimum—have been built, while extensive bicycle parking is provided.

Besides Bloomberg’s sustainable aspirations, however, Foster was keen to stress the role art plays in the building. Artists Michael Craig-Martin, Olafur Eliasson, Arturo Herrera, Cristina Iglesias, David Tremlet, and Pae White were all commissioned for site-specific works. The art act as wayfinding devices for the most part, and the most remarkable, Eliasson’s No future is possible without a past, resides on two floors. The Danish-Icelandic artist’s piece comes in two parts, the first topping a sinuous timber vortex lobby area and using a dappled reflective sheet of aluminum. (This dramatic lobby was the architects’ response to Bloomberg’s brief that called for an entrance that “gradually unveiled” itself.) The second piece is directly above on the next floor and is essentially the same, serving as a preamble for an even more spectacular walkway. Though elevators exist on the outer edges of each level, the walkway, which in mathematical terms is referred to as a “hyper-tricoid,” produces oblique views between office floors. The stepped ramp was contrived by rotating half of an ellipse 120 degrees on each level. The result is a serpentine path that spans a central atrium, connecting the second through to eighth floors.

Despite Michael Bloomberg’s derision of Brexit as “the single stupidest thing any country has ever done besides Trump,” his company’s new London HQ suggests it’ll be in London for the long-run. For all the climate testing carried out in Battersea, Brexit may be the biggest storm Bloomberg’s new headquarters will face.

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