It took almost a decade to build this building,” says Michael Bloomberg, former mayor of New York and head of the Bloomberg media empire, standing beneath the twinkling LED-studded ceiling of his new £1bn London headquarters. “Some people say it’s because we had a billionaire who wanted to be an architect, working with an architect who wanted to be a billionaire.”
The marriage of Bloomberg and Norman Foster – the only architect to have featured regularly on the Sunday Times Rich List, and to have renounced his seat in the Lords to protect his non-dom tax status – is a formidable combination, beyond just the might of their offshore bank accounts. Together they have created what purports to be the world’s most sustainable office building, and certainly one of the most expensive.
Standing in the middle of the City of London, occupying a 3.2-acre site between the high-tech bracing of Cannon Street station and the pink-striped stone galleon of No 1 Poultry, the 1 million sq ft hulk does its best to be a demure neighbour. “We were very conscious of being guests in London,” says Bloomberg. “We wanted something perfectly modern and eminently British that respected London’s traditions.” Over 9,000 tonnes of the same Derbyshire sandstone as the adjacent Victorian magistrate’s court have been used to clad the building’s chunky columns, which rise to eight storeys before stepping back for an extra two, matching the height of its neighbours.
“We could have gone a lot higher,” says Foster, “but Mike wanted to fit in. He has a keen sense of civic pride.”
The building is a radical departure from what Foster had proposed on the same site for a different client just a few years before, in collaboration with French architect Jean Nouvel. Nicknamed “Darth Vader’s helmet”, the previous scheme – which received planning permission in 2007 at the peak of the light-headed “iconic” architecture bubble – would have risen to 22 storeys, its sinister domed tower looming over the Mansion House. It was a wonky glass mess, the result of design-by-committee, lost in translation across the channel, and it was scrapped in 2009 when Spanish property company Metrovacesa pulled out.
Lurching from the outlandish to the timid, Foster’s redesign has almost retreated too far: the result has the prosaic air of a regional Debenhams. Its heavy stone columns march along the street, framing bulky bronze fins around the windows. Everything looks a bit too chubby, almost cartoonish, as if it was designed at a smaller scale and blown up to fit the site.
In a welcome move, the original Roman road of Watling Street has been reinstated, slicing a new diagonal route through the building, but it takes the form of a gloomy covered passage, heavily guarded by Bloomberg’s Seal Security team and rebranded as the Bloomberg Arcade. In a civic-minded gesture, there are three new public spaces at the corners of the site, adorned with water features by Spanish artist Cristina Iglesias, although her green-patinated bronze layers of matted foliage resemble fetid swamps – perhaps a sly comment on the financial services industry.
“Bloomberg wanted an outside that’s dignified and an inside that’s dynamic,” says project architect Michael Jones, leading a tour along the “vortex” ramp that winds in a trefoil spiral for over 200 metres through the building, connecting the office floors in a meandering loop. The usual central core of lifts and services has been broken up and distributed to the edge of the floors, opening up the middle and allowing views between the levels, where the 4,000 staff will work at bespoke sit-stand desks, up to 700 people to a floor.
The result is an extremely deep-plan, inward-looking office environment, where glimpses of the outside world are secondary to views back in to Bloomberg’s hubbub of “collaboration and teamwork”. You often feel very far away from a window, a sense exacerbated by the great bronze baffles that further block the view.
These are what Foster calls the “gills”, featuring flaps that open and close automatically, allowing the building to breathe, while softening traffic noise from outside. Further environmental cunning is to be found in the sparkly ceilings, which deal with lighting, cooling and acoustic attenuation in a slender 100mm sandwich. Inspired by the pressed tin ceilings of turn-of-the-century New York, they are covered with 2.5 million polished aluminium petals that serve as light reflectors, sound baffles and coolers, chilled by water from above. They create a starry sky above the endless field of desks, adding a fitting touch of Bloombergian razzmatazz to the scene.
The passive ventilation system – whereby air is drawn up through the building and exhausted through a central roof-light – is a big part of the reason the project achieved a sustainability score of 98.5% from Breaam, the body in charge of awarding green credentials. Bloomberg spared no expense, having a full-size mock-up built in a warehouse in Battersea to put these novel environmental strategies to the test. Foster says the resulting building uses 70% less water and 40% less energy than a typical office block, although the embodied energy levels are not slight, given that it contains 600 tonnes of bronze imported from Japan and a quarry-full of granite from India.
More impressive rocks are to be found in the basement, in the form of the ruins of the ancient Roman Temple of Mithras, which was discovered in the 1950s when the site was first excavated, and clumsily rebuilt down the road at the time. The remains have been returned, and will be open to the public in a dedicated space from November, alongside some of the 14,000 artefacts that were recovered during the excavation.
“Maybe 1,800 years from now,” says Bloomberg, “people will discover the ruins of our building too.” They may well marvel at this latter-day sustainable temple of financial reporting – if, by then, it hasn’t been painstakingly deconstructed post-Brexit, and moved with the rest of the industry to Frankfurt.