Cross-laminated timber (CLT) is a new, environmentally-intelligent material that is changing the way homes are built.
The next generation of builders, as well as people buying or building a new house, are getting excited about wood. Cross-laminated timber — also known as CLT — is creating hype for its architectural qualities, potential to help decarbonize the building sector, and promise to help produce more affordable high-quality housing.
A new way of building with wood
After the 21st century heyday of steel and concrete, wood has become popular in architecture. New ways of engineering wood have opened novel possibilities for the building industry. Specifically, a relatively new material called cross-laminated timber — also known as CLT — is stirring a lot of excitement in the building sector.
CLT was developed in the early 1990s in Austria, where softwood forestry has many similarities to the Finnish forestry industry. Producing the material involves layering solid logs of timber crosswise to create super-strong slabs of wood.
These can be as large as 5 meters long and 28 meters wide, and match or exceed the performance of both concrete and steel. This is why CLT can be used to make entire buildings, including structures, floors, walls, and ceilings.
Powering carbon-neutral construction
Sustainable construction is in high demand among environmentally-minded people who are either buying a new house or building their own. Compared with many other construction materials, building with massive timber CLT can significantly reduce carbon emissions as the massive timber continues to sequester carbon from the atmosphere.
Around half a ton of CO2 is emitted to manufacture one single ton of concrete, and two tons of CO2 to manufacture one single ton of steel. With family homes, swapping concrete and steel for wood, combined with the long-term carbon storage in CLT buildings, can altogether reduce nearly 75 percent of the total emissions of traditional construction.
Responsible sourcing of wood can cut emissions about 25 percent further. It is important that timber is sourced from FSC-certified forestry, which protects biodiversity and forest growth. Sustainable forest ecosystems provide not only carbon sequestration but also wild animal habitat and recreation.
Last, wood is a natural insulator. Softwood in general has about 10-times the thermal insulating ability of concrete and masonry, and 400-times that of solid steel. This reduces the needed energy for heating the house, further propping up the environmental credentials of massive timber CLT.
In addition to all the sustainability benefits of CLT, the material also changes the process of building altogether. Now houses can be constructed within weeks, with low labor costs, and virtually without material waste. But how?
After the design is configured to suit the needs of the owner and the site, the designer can send plans directly to the factory. This makes the process of architectural design significantly more efficient and saves both time and costs.
The wooden elements are precision-engineered in the factory and made exactly to specifications, with original design fidelity up to one square-millimeter. All the designed details, from door and window openings, to fittings for plumbing and electricity needs, are in the right places.
The precision-engineered CLT modules are then transported to the construction site exactly when required, avoiding inventory accumulation and minimizing disruptions and delays. The house is assembled on the site, creating up to a 50-percent faster process with less noise, dust, and pollution.
Where beauty meets utility
CLT is a naturally breathing, structurally stable, sustainable, and highly durable material. The functionality is further enhanced by its aesthetic appeal. The multi-sensuous qualities of CLT are incredibly rich — considering its visuality, acoustics, tactility, and scent.
Massive timber has sparked the interest and creativity of the building community with good reason. As you too plan to build, construct, or buy a house on your own plot, selecting CLT as a primary building material is a smart, next-generation construction choice.
Are you interested in building a new house on your plot? Learn about Asumma's carbon-neutral, timber design homes here.