Photo: Andre Pihl

With a 23 metre overhang and an advanced design Aula Medica is one of Stockholm's most innovative buildings in recent years.

Karolinska Institutet has long had an extensive active relationship with the wider community and therefore also a great need for its own meeting hall facilities. Yet no proper auditorium was built when the campus took shape in the 1930s and 40s. 

This finally changed in 2008.

Akademiska Hus and Karolinska Institutet had long been planning, together, a lecture hall on Campus Solna, and thanks to a private donation in 2008 from the Erling-Persson Foundation the project to design and plan Aula Medica got under way. Ground was broken on the project in September 2010. 

The demanding structure called for steel

To make the most of the limited space available at the site, the architects at Wingårdh came up with the bold idea of sloping the façade sharply outward and thus making each floor larger than the one below. The façade slopes as much as 33 degrees in places and the top floor has an overhang of 23 metres versus the perimeter of the ground floor below it.

Right from the outset, Johan Ström, Head of Section at COWI, realised the challenges that the project presented.

“The entire building challenges the laws of physics, to be sure. A heavy structure that slopes sharply outwards places great demands on the design of the structure and the choice of materials. Initially the intention was to have a wooden frame, but in the end it had to be steel to ensure the structure could cope with the strains,” says Johan Ström.

Photo: Tord-Rikard Söderström

The building’s supporting framework radiates out from the centrally located lecture hall, which has no internal columns and can seat an audience of up to 1,000 in addition to the stage area. The primary supporting trusses are housed on the top two office floors and radiate out in a fan shape from a common point of origin behind the stage.

Photo: Patrik Lindel

The trusses support two floors of office space, gantries above the lecture hall as well as the roof framework and the two technical installations located on the roof. The trusses follow the shape of the lecture hall and meet the curved and sloping glass façade to support the floor structure in the sloping section of the building. The two-storey-high steel trusses are housed on the office floors, freely supported 31 metres above the lecture hall.

“In order to support the floor structure in the sharply sloping sections of the building, we opted not to have each floor supported by the floor below. The considerable horizontal forces this would involve were inadvisable for the structure. Instead the upper floors are suspended from the supporting trusses,” says Johan Ström.

The floor structure that supports the terraced seating in the lecture hall was another technical challenge. It was necessary to combine large spans, heavy loads and also to satisfy a frequency requirement to ensure comfort and avoid vibrations. To complicate matters further, the floor structure slopes and follows the curved underside of the stand seating.

The solution was welded steel box girders with continuous anchoring by hollow-core slabs braced between the girders. This created a composite floor structure, in which the concrete structure strengthened the steel girders, while continuity was created for the floor slabs braced between the girders.

The advanced architectural vision of a building made up of triangles in both framework and façade was another challenge. Time expenditure, cost and quality were constantly in focus while the structure was being designed. 

The work was challenging, but paid off. In 2014, Aula Medica was named "Building of the Year," and won the International Award of Merit in 2015. COWI, together with Akademiska Hus, Wingårdh Arkitektkontor and steel contractor Normek, also won the Swedish Steel Structure Award in 2015. 

“I am incredibly proud of having been involved in and contributed to this beautiful building that has received so much positive attention,” says Johan Ström.