Searching for the most sustainable material we are usually thinking of the most technologically advanced one, with state-of-the-art constructive characteristics, made in a modern laboratory. But maybe that is not the case.
With the built environment industry generating 40% of the annual global CO2 emissions, there is no doubt that there is a dire need for a radical solution. In terms of sustainability and circular economy, we are in search of a building material that, in plain English, ends up where it comes from, thus completing a hypothetical life cycle, starting from the extraction process of the material and ending at the recycling phase by returning to raw material form.
In that case, steel or cement, which are the most broadly used materials, lack the feasibility of turning them back to raw materials or the process is highly energy and money-consuming. However, the solution could be found in simplicity and nature. Timber could probably be the one. It is claimed to be infinitely renewable and its production is indeed a part of a life cycle that, in essence, has the potential to be regenerative. Within the construction industry, timber is frequently regarded as the most environmentally sustainable building material, as it has a low embodied carbon footprint, measuring materials’ sustainability potential. At the same time, timber resources are infinitely renewable, whereas steel and concrete materials sources are not.
As the tree grows, it absorbs carbon from the atmosphere's carbon dioxide (CO2) and stores it for a limited time before releasing it back into the cycle. The construction's usage of wood only momentarily diverted carbon from the primary cycle. The structure is merely storing carbon like that of a tree, albeit in stasis as opposed to a living tree. More trees are planted, absorbing and storing carbon as they grow while this carbon is safely locked up in timber products like walls, windows, doors, and floors. Research reveals that more emissions are actually absorbed and stored in wood products that are released over the whole process of harvesting, processing, manufacturing, and transportation. This offers a method for reducing emissions on a net basis. At the same time, manufactured timber products demand much lower energy inputs to be created than rival materials, thus giving prominence to timber as a low embodied carbon material.
Indeed timber and its derivatives sound like an ideal alternative. It must be handled properly, though, just like any other building material, as the use of wood in a structure does not ensure sustainability by itself. Timber can actually be less environmentally friendly when used improperly in building design and construction than steel or concrete, hence proper education, in-depth knowledge, and hands-on experience in timber construction are required. Nevertheless, timber is by no means a cure-all. Some variables make wooden construction more or less appropriate based on the site of the construction, the prevailing location, weather, or phenomena, such as earthquakes. Therefore, wood’s structural characteristics have to be considered and its behavior towards the different encountered variables.