Netherlands-based architecture and urban design practice MVRDV has won the competition to build twisting 'hourglass-shaped' tower near Vienna's Gasometers.
According to the architect, the project site is adjacent to a metro station and regulations restrict new-builds to 75m-high. To overcome this, the company proposed a compact, square layout to reduce the footprint.
MVRDV will parametrically shape the lower ten floors of the building into a twist, so that the structure only casts a shadow onto neighbouring facades for two hours a day. The upper 20 floors will have a traditional square layout.
MVRDV co-founder Winy Maas said: "It is nice to see that if we take the two hour cast shadow regulation seriously, we are able to create an unprecedented tower.
"A tower with a slender 'taille'."
The individually shaped floors at the building's twist are said to be unique and offer outside spaces connected to one another by external stairways, to help enliven the lower part of the tower.
The building's curving 'waist' deflects fierce winds and the square layout is said to result in a net floor surface of 80% of column-free space and a 3.5m ceiling height.
The tower will be realised in a cost-effective structure of composite columns and concrete slabs. Its steel and glass façade will include operable windows and full-height French doors for natural ventilation.
The basement will provide parking space with 110 bays available.
MVRDV is said to have won the competition with Bollinger + Grohmann Ingenieure Wien and Energy Design Cody Consulting.
Image: MVRDV to construct twisting tower in Vienna. Photo: courtesy of MVRDV.