Observation Tower Kärven, White Arkitekter's Latest Spectacular Timber Building

The 12-meter-high and 7-meter-wide tower is constructed with 140 beams in a three-dimensional, web-like structure.

– We have worked with well-known timber dimensions. A 2"x4 beam, I believe, is something most people can relate to; it's almost a symbol of timber construction. They create a pattern from a distance but are something you can fit in your hand if you get closer, says Lukas Nordström, Lead Architect in the later stages.

Kärven is a hybrid structure that utilizes its materials in their most natural way. The building components – classic timber beams combined with cut-out metal rings – have enabled a smooth assembly process carried out by local contractors without the need for special tools. Each beam was installed on-site in approximately two minutes, and the total assembly time for the timber beams was just over a week.

Based on the constructive principle of a hyperboloid, Lukas Nordström and his colleagues sketched out the supporting structure that would become the winning entry in Varberg Municipality's architectural competition in 2019.

Behind Kärven's iconic appearance lies a construction that would not have been feasible without advanced modelling and calculation technology. The general principle of the hyperboloid form is simple and purely mathematical. However, to test and delve into such an unconventional design proposal in a relatively short time requires design speed. While working on Kärven, the team also explored several constructive principles in parallel. The parametric design software Grasshopper made it possible to create the mathematical relationships for the design and develop them into digital and physical models, which in turn helped the team to make quick decisions.

Kärven is an example of skilful interweaving of architecture and construction, resulting in strong and sustainable architecture. The good cooperation and knowledge exchange with structural engineer Niklas Johansson at Rambøll has been crucial, according to Lukas Nordström, Lead Architect in the later stages of the project, following Ulla Antonsson and Mattias Lind who were both involved in the early stages. 

– Kärven's concept has required an understanding from both architect and structural engineer of each other's disciplines. This has resulted in a design where it is impossible to say where architecture ends, and construction begins. By starting with a supporting construction principle and then creating architecture from it instead of the other way around, we had a logic from day one. We never had to compromise to force it into the architectural form afterwards, says Lukas Nordström, Lead Architect in the later stages.