Wood in construction: what works and what is questionable?

Architects and engineers are working hard to push the limits of timber construction. Wood was once thought of as a material only for small buildings, but today it is capable of surprising us. Thanks to advanced technologies such as CLT (cross-laminated timber), timber structures are becoming strong, fire-resistant, and suitable even for high-rise construction.

Wood has enormous potential as a material to replace steel and concrete.

Wooden structures, for example, are easier to transport and install, which cuts time and labor costs on the construction site. The material's lightness and workability allow for shapes that would be difficult and costly to achieve with concrete.

According to researchers at Wageningen University and Research in the Netherlands, wood is an excellent choice for buildings up to 60 meters tall.

Beyond that height, the advantages of wood begin to diminish compared with traditional fossil-based building materials.

Carbon footprint and environmental benefits

The biggest advantage of wood in construction is its environmental friendliness. Concrete and steel production accounts for nearly one-third of the world's carbon dioxide emissions, whereas timber construction not only avoids adding CO₂ to the atmosphere, it actually “traps” it. Wood absorbs carbon dioxide as it grows, and that carbon stays locked in for as long as the wood is used as a building material. As a result, a single wooden building can offset the carbon footprint of several concrete or steel structures at once.

Growing and using wood takes far less energy than the extraction and production of traditional materials, which only strengthens wood's case as a sustainable choice.

Challenges still to be solved

• Fire resistance. Although wood can be made more fire-resistant, its behavior in a fire remains a serious concern, especially for high-rise buildings. For such projects, it is common to use layers of CLT that protect the inner wood components and provide a certain level of fire resistance. However, fire-safety standards for tall timber structures are still emerging, and each country is developing its own requirements.
• Weather and pest resistance. Moisture can be the enemy of wooden buildings, since prolonged exposure to water can cause rot. Protective coatings and regular maintenance solve this problem, but they add to operating costs. Wood can also attract insects, which calls for treatment with preservatives.
• Building codes and standards. Unlike steel and concrete, wood is only beginning to become the norm in high-rise construction, so many countries do not yet have strict standards for such structures. This holds back the development of tall timber buildings, because investors and developers cannot be entirely sure that they are safe.

How far can we go?

To date, there are already several tall wooden buildings that approach the height of traditional skyscrapers. For example, Mjøstårnet in Norway, an 18-story wooden building 85.4 meters tall, is considered the tallest wooden skyscraper in the world. And recent designs promise to go even further, showing that the limits are a matter of technology, not of the material itself.

What does the future hold?

In the future, timber construction could become the foundation of green cities. Because wood is renewable and easy to recycle, many cities are considering it as a key material for sustainable construction. As CLT and other technologies keep improving, wood can become even stronger and safer, making it possible to build ever taller and more complex structures.

Wood as a building material therefore holds enormous potential. It offers a sustainable alternative to concrete and steel, making it possible to build durable, stylish, and practical buildings that can form the foundation of the cities of the future.