BLACKPRINT: Mr Elgsaas, Mjøstårnet is considered the tallest timber building in the world. How did the project come about, and what was your vision for it?

Øystein Elgsaas: It depends how you define 'height'. If you also include hybrid buildings, there are now a few that are slightly taller. But as a fully timber structure without a reinforced concrete core, Mjøstårnet remains the tallest timber building in the world. The project goes back to the initiative of property developer Arthur Buchardt, head of AB Invest, who grew up in Brumunddal himself. The construction company Hent AS and the supplier Moelven were also involved, both of which specialise in timber products. Together, the idea emerged to realise a project that would make the capabilities of modern timber construction internationally visible and show that timber can be used economically and safely even at high-rise scale.

BLACKPRINT: What was the greatest challenge in realising the project?

Øystein Elgsaas: The entire project broke new ground from the very beginning, and accordingly we had hardly any empirical data for a project of this size. As a result, there was very little precedent for how all the elements would perform together, what dimensions the timber columns would need to have, for example, or how we could reliably ensure fire safety. We therefore had to do a great deal of research. Close collaboration with everyone involved was crucial: engineers, manufacturers, the construction company and our team developed solutions, tested them again and again and refined them. In the end, everything worked very well.

BLACKPRINT: In many cases, compromises were surely necessary too, weren’t they?

Øystein Elgsaas: Yes, the timber columns in particular were a challenge: we wanted to leave them exposed, while at the same time fire safety regulations require protective measures. It was a matter of striking a careful balance. Ultimately, we were able to show that glulam columns and beams are very safe compared with a pure CLT structure and meet all requirements. Acoustic insulation and building services also presented us with complex tasks. Large timber elements transmit vibrations, and installations must not weaken load-bearing components. That is why we kept everything as simple as possible, worked with standardised details wherever we could and relied heavily on prefabrication. This shortened the construction time while increasing precision.

BLACKPRINT: And what about the authorities? Did you have their support, or was the collaboration rather difficult?

Øystein Elgsaas: The local authorities were genuinely cooperative. Of course, some building regulations had to be adapted with regard to the height of the building. And in many cases there was initial scepticism, too. Some people joked, for example, that we were not building the world’s tallest timber building but the world’s tallest bonfire. Yet using timber is by no means as risky as is often assumed. In the end, we were even able to prove that, thanks to all the comprehensive safety measures, Mjøstårnet ranks among the safest buildings in all of Norway.

BLACKPRINT: The building brings together flats, a hotel, a restaurant and public spaces under one roof. How did this mix of uses influence the design?

Øystein Elgsaas: Combining the various functions was a real challenge. Normally, a building follows a clearly defined structural grid. In this case, we had to work without a fixed system, which made the design phase correspondingly complex. As a starting point, we then chose a classic hotel layout: two rooms side by side, a corridor in the middle. We then examined whether two or three hotel rooms could be combined into one flat and which elements could remain constant across all levels. The 1 x 1 metre columns were particularly demanding. We asked ourselves whether these elements would be accepted in the middle of a flat or whether we would have to adapt the floor plans. Interestingly, it was precisely the flats with exposed columns that sold the fastest in the end. People appreciated the distinctive character and the tactile presence of the timber.

BLACKPRINT: And how did the design of the façade come about?

Øystein Elgsaas: The façade design is ultimately very strongly shaped by the load-bearing structure, as the diagonal elements of the timber construction influenced window positions, balcony access and the entire façade structure. As a result, all levels were given a cladding of timber panels and louvre-like elements that extend across the building in a rhythmically recurring pattern.

BLACKPRINT: How is the façade of Mjøstårnet ageing now, after a few years?

Øystein Elgsaas: The façade has weathered slightly faster than we expected. At the beginning, we discussed whether the façade should visibly consist of timber at all. For the client, however, it was crucial that you could immediately tell from the outside that it is a timber building. So we chose a type of wood that ages well and also used special screws so that nothing rusts. At one point, we also considered placing a glass façade in front of the timber façade. But with the strong temperature fluctuations in Norway, from 30 °C to −30 °C, this would have created many thermal bridges, and we did not want to risk that. It would also have made the building considerably more expensive. So while the building is somewhat more costly than a conventional one, in return we were able to build much faster, more cleanly and more quietly. As the system becomes increasingly standardised, costs will continue to fall in future.

The façade structure of timber panels and louvre-like elements extends across the entire building in a rhythmically recurring pattern.

BLACKPRINT: How important was the use of regional resources for the project?

Øystein Elgsaas: That played a major role. We like to say: if you stand at the top of the visitor platform, you can see where the material for the building comes from. Most of the timber comes directly from the region. Of course, we also had to import some material, such as CLT elements, because Norway did not have sufficient production capacity for our needs. For the load-bearing structure itself, however, we used exclusively local timber – the production facilities are only about 15 minutes from the construction site. The façade elements were also manufactured close by. The entire production chain was extremely short, from the sawmill to the factory to the construction site. That is not only ecologically sensible but also strengthens the region: the economic benefits remain within the local community, jobs are created and people identify with the project.

BLACKPRINT: Regional as it is, the project has nevertheless attracted considerable international attention...

Øystein Elgsaas: Yes, the project has reached people from all over the world. We had visitors from China who asked us to collaborate on a timber project there. Or architects from Denmark who are now realising a timber building in Sweden. As a result, I am very grateful to have been part of this project. I have been to Canada and Denmark, exchanged ideas with architects from Zurich, Brazil and the USA, and spoken with journalists and television stations. Internationally, We've arguably received more attention internationally than we have at home in Norway.

BLACKPRINT: In parallel with Mjøstårnet, you also developed the master plan for the surrounding district. One office building has already been completed. What else is planned?

Øystein Elgsaas: Yes, the new office building stands on a plinth with five storeys used as office space. As with Mjøstårnet, the main structures are made of glulam with a core of solid timber, and the façade also picks up on the architectural concept of its neighbour. The aim of the building is to continue the idea and the success of the extensive use of timber as a building material and to create a harmonious overall design for the district. Further buildings are being planned. Adjacent to it, we have also developed a small public park, and on the lakeshore there is now a small harbour for boats. In addition, we have designed a tent-shaped cultural building. It is intended as a public and cultural centre, with a stage for events. We are confident that the project will be realised.

In line with the master plan by VOLL Arkitekter, the area around Mjøstårnet is gradually being transformed into an attractive district for living and working. The office building on the left has already been completed.

BLACKPRINT: In addition to flats and public functions, Mjøstårnet also integrates a hotel. You have realised another sustainable hotel in Trondheim. How did that project come about?

Øystein Elgsaas: Yes, we have already designed several hotels and know the processes very well. The Scandic Hotel Lerkendal in Trondheim is one of the most energy-efficient hotels in the world; alongside hotel rooms, it also combines a conference section and three floors of office space. Our approach at the time was particularly focused on energy efficiency: small rooms require less energy, while large windows increase heat losses. We therefore reduced the window area to just ten per cent of the façade, precisely arranged like a game of Tetris. Depending on the season, the building can produce more energy than it consumes.

BLACKPRINT: In Molde, you are currently working on another hotel project that combines existing buildings with new construction. What particular challenges and opportunities arise from this?

Øystein Elgsaas: The site is located directly on the fjord. That is why we are planning a publicly accessible ground floor, so that not only hotel guests but other visitors too can enjoy the magnificent view. At the same time, we are carefully examining which elements of the existing structure we can reuse and which materials can be used again in future. Because ultimately, it comes down to this: many of the buildings we will be using over the next 60 years already exist today. It is often more sustainable to continue using existing structures than to build completely new ones.

On the fjord shore in Molde, VOLL Arkitekter are planning the Superb Hotel, which combines old and new into a single complex.

BLACKPRINT: These are all very different projects. How would you describe your practice’s philosophy today, and how has this attitude evolved over the years?

Øystein Elgsaas: Over the past 15 years, our focus has increasingly shifted towards sustainability. Two weeks ago, we received environmental certification that commits us to consistently implementing sustainable decisions and solutions, both in the organisation of our office and in our projects. This also includes encouraging clients to adopt better solutions or showing them alternatives that are often more efficient and more durable than their original ideas.

BLACKPRINT: Alongside reducing CO2 emissions, adapting to the consequences of climate change is also playing an ever greater role. What challenges do you see here for architecture?

Øystein Elgsaas: I see flood protection as the central issue above all. With Mjøstårnet, we therefore also had to take a a 1-in-200-year flood event into account and additionally allow for one metre of reserve in case extreme weather events occur. Even scenarios such as a storm combined with a fire in the tower were examined. As a result, we raised the entire site slightly so that emergency services can operate even during flooding.

BLACKPRINT: Considering the technical and ecological challenges, the question arises: what role should architects play in future?

Øystein Elgsaas: Many architects see themselves as creative geniuses who think they have to know everything. But of course that is not true. We are a small practice with eleven employees, eight of them architects, and we cannot cover everything ourselves. Tasks such as energy planning, material cycles or digital models require specialists. Our role is rather to set the framework and develop a sustainable overall concept. On this basis, we bring expertise together and design buildings that are architecturally convincing and fit well into their surroundings.

BLACKPRINT: Given these rapid developments, how do you keep up to date yourself?

Øystein Elgsaas: We make an effort to stay up to date here. But in our profession you quickly become ‘old’, because everything is constantly in motion. That is why we attach great importance to an intensive exchange with the younger generation. In March, for example, we had a meeting with architecture students here in Trondheim – a kind of ‘table talk’ about architecture in general. We took part in it partly to find out what matters to the next generation. After all, it is today’s students who will shape our profession in the future.

BLACKPRINT: Mr Elgsaas, thank you very much for this conversation!

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