Kungsbrohuset, in Stockholm, is one of the greenest buildings in the world, and recently sold to a Swedish insurance company for €200 million.
It was built by Jernhusen who wanted to construct a building that would last the test of time, and be a monument for the city. They decided that this could be achieved by focussing on energy efficiency, and it has now become a blueprint for modern green buildings.
Klas Johansson, the chief sustainability officer, said that they are “extremely surprised no one has done this before us, there is no logical reason why you wouldn't.”
“Everybody on the project had to think about solutions,” he said. “The people designing the façade, the people doing the lifts – everybody was thinking what can I do to make my bit more energy efficient.”
Easy savings were made by using triple glazed windows, and providing just 100 car parking spots for the 2,500 workers who inhabit the building. But other savings made use of clever techniques such as providing a button by the exit of each office which turns off all lights and non-essential electrical systems when the last person leaves the room.
Offices generally need cooling systems due to the computers, servers, and other machines, so Jernhusen ran a pipe from the lake outside to use the cold water as the main part of the cooling system. The heating system also uses naturally occurring heat; heat from the passengers in the subway. Normally the stations must be constantly cooled due to the heat emitted by passengers, but Jernhusen, who conveniently owns Sweden’s railway and subway stations, uses that heat to warm the Kungsbrohuset building.
Johansson tells an interesting story of when they were designing the heating system. “When we sent the authorities a map of where we wanted to drill, they said you can't drill there. When we asked why not, they said we can't really tell you.”
“It turns out the central station is a security object for the military. The idea was that we had to have tunnels in order to conduct guerrilla warfare in the event of a Russian invasion. So there are secret tunnels that aren't marked on maps.”
“We would have to send plans to the authorities and they said yes or no.”
Jurnhusen has plans to build similar projects in Malmo, Gothenburg, and another in Stockholm in over the next decade.
By. Joao Peixe of Oilprice.com