Cheaper transportation and less hassle on-site

Using lightweight materials, such as wood elements, benefits the constructor and puts less pressure to the surrounding infrastructure. Material handling and internal logistics on-site are reduced, which in turn leads to less waste production. Furthermore, lighter construction materials are less costly and more energy efficient to transport.

“Depending on material and transportation distances, logistics can form an important part of all production costs, ranging from 12 to 30 per cent. Research has shown that if materials are provided by one central supplier instead of many, 6 per cent cost savings in logistics can be accomplished,” Matti Kuittinen, architect and researcher from Aalto University, points out.

Light load - less fuel needed

Values guide Metsä Group's operations

Lighter material load improves fuel efficiency

One significant cost in logistics is the consumption of fuel. It has been shown that in a situation where the distances from the factory to the construction site and the terrain profile of the route were the same, the transportation of Kerto® LVL element had the lowest CO2 emissions and the best fuel efficiency.

“To clarify, if building elements that fulfil comparable function in the building can be loaded into the truck in similar quantities, the lighter element load will improve fuel efficiency,” Kuittinen says.

Improving on-site material handling

Improved material handling

Wood elements enable easier material handling

Material handling at the building site may take up 14 per cent of working time and can control up to 80 per cent of the schedule of the entire construction project. Prefabricated building products may improve the efficiency in material handling. For example, Kerto LVL elements are large, but light, hence the amount of square metres of material per lift is more than with smaller, but heavier elements.

“Material handling should be minimized, as it only adds costs, not value to the product. Ideally, individual sub-components should be combined into a single “unit load”, which can be more effectively handled at the building site,” says Rune Abrahamsen, CEO of Moelven Limtre AS, the general subcontractor for the world’s tallest wooden building, the Mjösa Tower, completed in 2019.

Efficient logistics in varying environments

Values guide Metsä Group's operations

Lighter logistics is important in the urban growth areas

In growing urban areas, the importance of lighter logistics and material handling is high-lighted. Efficient logistics decrease noise and pollution, increase traffic safety and have a positive impact on the local economy.

For example, the extension structures of the Paris Police headquarters had to be built fast, since the site was in a busy area in the old centre of Paris. The pre-fabricated elements were brought to the site at night and erected during the day. The light wood was handled on the site without the need for heavy machinery, so the drawbacks caused by building in the busy city centre were minimized.

SPA-Bungalow

Remote locations reachable only by helicopters

Another example of innovative lightweight construction comes from Switzerland in the form of the SPA-Bungalow, a small transportable spa complete with sauna, bathroom and shower, and a relaxation area with a bed. The bungalow is ideal for both a few hours of relaxation and overnight stays. The entire bungalow is built with Kerto® LVL elements, and can be transported as modules to remote locations: the first one was helicoptered to Lötschenpass, a stunning location in the Alps at an altitude of 2690 metres, and ready to use within a few hours of arriving.

“Lightweight construction provides many sustainable solutions, such as building new storeys on top of existing buildings out of ready-made modules, or for building small, transportable houses that fit into the yards of larger houses. The world’s urban infrastructure is going through a major transformation and using lightweight construction products instead of heavier components is the way to a more efficient and sustainable future,” Roger Bernet, the designer of the SPA-Bungalow concludes.

Architect, research manager
Matti Kuittinen is Research Manager and Architech in Aalto University, School of Arts, Design and Architecture. His research and lecturing work at Aalto University is focused on wood construction, carbon footprinting, LCA, energy efficiency and humanitarian aid.