According to some demographic forecasts, today’s global population of 7 billion could well be 9 billion in 2050... So we need to build all the houses and apartment buildings needed to accommodate all these people! That poses an enormous ecological, financial and societal challenge for all construction industry stakeholders, and begs a central question: how can we build better, faster and more virtuously?
Lightweight construction could provide a key response. This construction method uses materials like timber and metal to form building structures, instead of bricks and mortar. Far from being a fashion statement, this trend is essentially the globalisation of local traditional construction methods. Don’t forget that in Scandinavia, Japan and the USA, timber-frame construction is the norm! In the USA, 90% of all single-family homes are built using modular timber structures. In Norway, the houses designed by Norges Hus are built using this principle. Healthy and environmentally friendly, they comply fully with the latest thermal insulation and energy efficiency regulations. And let's face it: they have nothing in common with a log cabin!
Lighter weight with equivalent performance
“Lightweight construction offers a number of advantages”, explains Gilles Leva, Deputy Vice-President Marketing at Saint-Gobain. “For example, timber structures are much lighter than concrete ones, which is a major benefit in itself, especially in terms of extending existing buildings or adding an extra floor...” It’s an option that opens up new opportunities, because although the majority of extensions have involved single family homes until now, the combination of timber and concrete is now increasingly common in the urban landscape, and points the way to tomorrow’s cities. Cities that are more vertical. More virtuous. More responsible.
London stood out distinctively as early as 2009, with the first 8-storey timber building, the Stadthaus. It was the highest in the world at the time! Since then, projects using timber in the construction of tower blocks and other buildings have sprung up worldwide. Timber is widely used in traditional Japanese construction, so even the new Olympic stadium in Tokyo has a structure of cedar and larch.
Timber is a strong performer
There’s no denying that in terms of carbon footprint, timber is a strong performer. By trapping CO2 throughout its growing life, this eco-material offers significant benefits in terms of reducing greenhouse gas emissions. The fact that it is a natural resource is another strength, because it is easily recycled and contributes to sustainable forest management. “That’s the other great advantage of timber!”, continues Gilles Leva. “Prefabricating timber frames facilitates rapid construction, and equally simple demolition! So from this point of view, timber is fully consistent with eco-responsible construction”.
But timber does not have the answer to everything because this resource is not unlimited and requires a reasoned exploitation. In order for timber construction to establish itself in the long term in places where it is not a traditional method, it will have to rely on the establishment of a professionalized timber industry and networks of dedicated prefabricators and installers to guarantee competitiveness and quality.
Is lightweight construction economical?
Is lightweight construction really more flexible, faster and more economical? It all depends on what we are talking about.
By offering the option to build faster, facilitate automation and optimise production processes by using prefabrication, lightweight construction really does reduce production costs, and therefore the construction costs of creating the affordable, repeatable and exportable housing the world badly needs.
But all that depends on the materials you choose. Timber frame or metal frame? The cost depends on resource availability. The fact that timber is widely used in Japan, Scandinavia and the USA is because the resource is readily available in those countries, and the construction industry has structured itself to use this material over a very long period, thereby keeping costs under control. Conversely, timber is clearly a scarce resource in the Middle East, making timber frame an inevitably expensive technique here.