The Royal Institute of British Architects (RIBA) has declared Foster + Partners the winner of the 2018 Stirling Prize, Britain's most prestigious architecture award, for its new Bloomberg headquarters in London. The massive project is impeccably designed and boasts considerable sustainable technology.

Bloomberg London could hardly be more different than 2017's community-minded winner Hastings Pier. Conceived as the media giant's European headquarters long before Brexit was considered likely, it is widely reported to have cost £1 billion (US$1.3 billion) and takes up an entire block in the City of London. It's thought, says RIBA, to be the largest stone building in the City since St Paul's Cathedral, which dates back to the 17th century.

Bloomberg London actually consists of two buildings joined by a bridge. The buildings are situated either side of a new public arcade that re-establishes an ancient Roman road. Elsewhere, the scheme ensures easy access to transport links, a museum displaying the Roman Temple of Mithras (discovered on the site 60 years ago), and cafes and restaurants.

They're finished in 9,600 tonnes (10,752 US tons) of sandstone and enlivened by decorative bronze window ventilation fins. Visitors to the main entrance find themselves in the "Vortex," a large area comprising three curved timber shells. From here, high-speed elevators provide access to the 6th floor "Pantry," which includes a large concourse and cafe spaces, with views of the City of London.

As you'd expect, a good chunk of the rest of the interior is taken up by workspaces and meeting rooms, mostly arranged in open-plan layouts. Ergonomic additions like electrically-operated adjustable work desks are meant to foster a pleasant working environment.

While it's a bit of a push to call this stone behemoth the world's most sustainable office, as Bloomberg does, it was awarded the highest ever BREEAM rating (a green building standard) and Foster + Partners deserves credit for going to great lengths to maximize its energy-efficiency.

Indeed, according to Bloomberg, it saves 73 percent in water consumption compared to a typical office building, as well as 35 percent in energy consumption. It includes rainwater capture, greywater recycling, natural lighting, and smart ventilation systems. Additionally, energy-efficient smart ceilings automatically regulate acoustics, temperature and light.

"Bloomberg is a once-in-a-generation project which has pushed the boundaries of research and innovation in architecture," says RIBA's judges. "The design brief called for a building which could rise-up to the challenge of this loaded site and an information-driven environment. The architect worked exhaustively and collaboratively to design a building which perfectly responds to Bloomberg's ambitions.

By building at a lower height than approved at planning, reserving parts of the site for public space, and using highly-detailed, handcrafted materials, Bloomberg shows a high level of generosity towards the City. This is a building of its place. Art has been commissioned as an integral part to enhance people's experience of the spaces."

The result of the Stephen Lawrence Prize has also been announced. Named after a black British teenager who was aspiring to become an architect before being killed in a racist attack, it highlights outstanding projects built to a relatively small budget.

Architects Tonkin Liu was declared the winner with its Old Shed New House, which involved turning an agricultural shed in Yorkshire into a plush home with its own private library and art gallery. Large amounts of insulation, as well as high levels of air tightness, mechanical ventilation, and heat recovery systems, make this fantastic retirement home efficient to run, year-round.

"This impressive project has brought life back into a redundant agricultural building to create a breath-taking new home," says Stephen Lawrence Prize founder Marco Goldschmied. "Using sustainable, low-cost materials, Old Shed New House illustrates perfectly what a talented architect can do with a fairly modest budget. The Foundation is delighted to present Tonkin Liu with the Stephen Lawrence Prize 2018."

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