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  4. Karven Observation Tower

Extraordinary collaboration. Simple, affordable building elements. Generations of knowledge reimagined for a sustainable, digital age. Kärven Observation Tower is already an icon, a symbol of nature’s beauty and the infinite possibilities of geometry. With its architecture and engineering one and the same, it shows the world how we can create more with less. 

Kärven’s positive impact shows we were right to be brave and do something different. It’s already given us so much back and become an iconic signature for the area. Doubling the number of visitors to Getterön while giving local people a new destination to make their own.
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Client

  • Varberg Municipality

Architect

  • White Arkitekter 

Project Status

  • Completed 2024

Awards

  • Varberg Municipality’s Architecture Award 2024 / Architects Sweden Halland’s Architecture Award 2024

Visit Getterön Nature Reserve in Varberg, Sweden and you’ll look out across an abundant wetland where land and sea meet. You’ll spot a diverse variety of birds, attracted by the reserve’s rich habitats. The earth beneath your feet. The tang of salt in the air. You’ll also see a timber observation tower reaching 12 metres into the Scandinavian sky. A strange, three-dimensional puzzle that looks both curved and straight. As you climb its winding stairs for a birds-eye view of the world, you wonder…how did it get here, how was it made? 

The story starts in spring 2019, when Varberg Municipality launched an architectural competition to create the perfect landmark observation tower for Getterön. Uniquely symbolic, yet simple and functional, an integral part of the nature reserve.

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A shared passion for geometry

Lukas Nordström, Lead Architect at White Arkitekter knew just the person to help create a winning design. They had studied architecture and engineering together at university and shared a passion for geometry. 

Over coffee, Lukas shared his ideas for Getterön with Dr Alexander Sehlström, Principal Structural Engineer at WSP Sweden. The two started work to develop a concept where expressive architecture and structural engineering intertwine. 

The impact of collaboration

Kärven Observation Tower is woven from 140 straight wooden beams – creating a 12-metre tall, 7-metre-wide hourglass-shaped silhouette. Its geometry takes the form of a hyperboloid’s double-curved surface. To the eye, it resembles a bunch of harvested grain stalks tied together – Kärven translates to ‘The Sheaf’ in English. What made it possible is the extraordinary collaboration between the client, architect and engineer. 

Since opening to the public in August 2024, the free to access structure has captured visitors’ imaginations and intrigued curious minds across the world.

Anna Baeck, Varberg Municipality’s Project Manager explained: “The tower stands on a former landfill site – the flagship in a new ecological recreation area we’re creating in collaboration with the community. It’s become a natural meeting point for people of all ages. Bird watchers are here early in the morning. Families visit throughout the day to picnic and play. Schools come to learn about nature. Young people meet and watch the sunset together.

What I love is how the tower changes. The sunlight and shadows interacting with the structure as you watch it from afar. Seeing bees, butterflies, then birds as you venture higher, the landscape reaching out in front of you from the open-air observation deck.”

Everything in nature is perfected, with nothing wasted. By using geometry and working together, we’ve made Kärven in the same way.
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Innovation propelled by technology

Alexander provided technical advice on the design concept and developed a parametric calculation model to analyse the geometry, connections and structural mechanics. It showed the tower would be structurally sound, yet sculpturally evocative.

After winning the competition, the same collaboration propelled Kärven’s detailed design and assembly. Alexander was appointed as an independent third-party reviewer. The role gave him the freedom to step back, work across architecture, engineering and construction, and push to make the project even better. From improving the durability of timber beams to simplifying their replacement during future maintenance.

The biggest challenge was how to connect the inner and outer timber beams making up the double-curved surface, as bolts would need many precisely drilled holes. The solution? Ten evenly distributed steel rings. A combination of digital parametric models and 3D printed physical models enabled this kind of exploration and evolution at pace – with everyone involved.

Beyond the structure itself, Kärven represents the point where architecture, engineering and geometry meet right now. The project team’s collaborative insight, experience and passion has been captured in a research report – already presented internationally.

Meet the Visioneers

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“Once the site at Getterön was ready, the tower took just five months to construct. The hard work done during the design stage simplified assembly, with the timber beams installed in a week” explains Dr Alexander Sehlström, Principal Structural Engineer, WSP in Sweden. 
When Lukas reached out, my first thought was ‘let’s do this’. What really appealed was the opportunity to show you can do cool stuff with geometry on a standard construction budget. Beautiful architecture that’s also resource efficient. Back in the day, geometric architecture was labour intensive to construct. Now with modern methods of construction to simplify things, there’s no reason it couldn’t make a comeback.

Other challenges that we have overcome