The world’s tallest fire-resistant wooden building is 85,4 meters high, has 18 floors, and a CLT structure capable of withstanding flames for more than 120 minutes according to European standards
In the interior of Norway, on the shores of Lake Mjøsa, one of the most impressive projects of contemporary engineering was erected: the Mjøstårnet, officially recognized as the tallest wooden building in the world. With 85,4 meters, distributed in 18 floors and built almost entirely of CLT (Cross-Laminated Timber) Engineered timber in cross-laminated panels, the skyscraper redefines everything that was understood about structural safety and fire resistance in large wooden buildings.
Opened in March 2019In the municipality of Brumunddal, the building has become a global landmark for sustainability, industrial precision, and innovation, proving that wood can not only match but surpass the performance standards of steel and concrete in several technical aspects.
Wood that doesn’t catch fire like regular wood: the secret of CLT.
The idea of building a skyscraper out of wood might seem risky, especially for those who imagine that wood is inherently flammable. But Mjøstårnet uses CLT, an industrialized material in which layers of wood are glued together in crisscrossing directions, forming solid panels with:
- high mechanical strength,
- Rigidity comparable to concrete,
- controlled deformation capability,
- predictable behavior in fires.
CLT chars externally when exposed to fire, creating a protective layer that prevents the inner core from being affected. This allows the panels to remain stable for extended periods.
European safety tests demonstrate that CLT panels can withstand for more than 120 minutes exposed to fire, the time is far greater than that required by various international standards for tall structures.
It is precisely this behavior that allowed Mjøstårnet to be approved by the rigorous Scandinavian standards.
Millimeter-precision engineering
The building was designed by the firm Voll Arkitekter and built by the company Hent. The entire structural system uses wood.
- glulam columns (glued lamellate),
- structurally engineered beams for long spans,
- CLT panels as load-bearing walls,
- Rigid cores also made of engineered wood.
The assembly was done like a “giant structural Lego”: the pieces arrived ready-made and numbered directly from the factory, allowing for quick assembly with minimal waste generation.
The building is still in use strategically positioned metal connectors, ensuring extra rigidity against lateral loads such as strong winds at height.
Sustainability at the most advanced level.
Beyond its visual and technical impact, Mjøstårnet has attracted worldwide attention for its sustainability:
- The wood used came from certified Norwegian forests.
- The building sequesters CO₂ throughout its entire lifespan.
- There is a significant reduction in environmental impact compared to concrete.
- Construction emits fewer greenhouse gases.
According to estimates from the engineered wood industry, replacing concrete with CLT in buildings above 8 stories could… reduce emissions by up to 75%.
This positions the Norwegian skyscraper as one of the most environmentally efficient buildings ever constructed.
A functional building: hotel, offices, apartments and swimming pool.
Mjøstårnet is not just an architectural experiment; it’s a multifunctional building. Inside, there are:
- residential apartments,
- a complete hotel,
- restaurants,
- offices,
- commercial spaces,
- auditorium,
- and even a heated public swimming pool connected to the structure.
Each space was designed to take advantage of the natural aesthetics of wood, creating warm interiors, controlled acoustics, and a superior sense of thermal comfort compared to traditional buildings.
How does it perform against wind, fire, and load?
Scandinavian engineers claim the building was exhaustively tested using digital simulations.
Fire resistance
The thickness of the panels was designed to allow for carbonization without loss of structural stability.
wind resistance
The height of 85,4 meters requires advanced lateral stiffness. This was achieved with CLT cores reinforced by glulam beams.
Resistance to vertical loads
Laminated columns perform similarly to steel in compression.
Durability
Engineered wood does not rot when properly protected from moisture, and the Norwegian climate facilitates this control.
A project that paved the way for new wooden skyscrapers.
Following Mjøstårnet, the global construction industry began to seriously discuss:
- hybrid buildings (wood + concrete),
- skyscrapers up to 150 meters tall made mostly of CLT (Cross-Laminated Timber).
- Faster and cleaner construction in urban areas.
- Reducing emissions from the concrete industry.
Cities like Vienna, Toronto, and Tokyo are already studying even taller structures, inspired by the Norwegian success.
The skyscraper that redefined the future of construction.
Mjøstårnet proved that wood is not synonymous with fragility. On the contrary: in the form of CLT and glulam, it becomes one of the most efficient materials for high-rise buildings, combining aesthetics, safety, and sustainability in a single project.
With 85,4 meters, 18 floors With proven technical strength, the world’s tallest wooden building not only defied concrete, it paved the way for a new era in civil construction, where technology, nature, and engineering walk hand in hand.
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