Why should we build with wood?
Why should we build with wood?
Wood swells, shrinks, splits, burns, rots, and changes color. But, worse yet, it is a material that, if we want to use it in construction, we have to cut trees. After all these facts, why then should we build with wood? The answer requires an argumentation that will have to take into account other questions that arise immediately: Why was wood used in the past? Why was it abandoned at a certain point? Why are we living a wood renaissance? If we use wood, what are the implications for the forest?
Even if we can justify the use of wood in other countries, can we do it for Portugal as well?
Let’s start from the beginning. Historically wood was used because of convenience. It was used when and where it was the easiest resource to obtain. In other cases, even with other materials available, it ended up being chosen because of its good behavior. Such was the situation of roof and floor structures, where its lightness, combined with its resistance, made it a material without competition.
Apart from the exception of some regions that stubbornly persisted, throughout History, in building with wood, most institutional buildings, meant to last, were built with stone or brick. From the nineteenth century on, with the access to building materials, such as steel and concrete, the trend for the substitution of wood was extended to other domains of construction. We could summarize that the abandonment of wood is justified by two obvious factors: wood is not durable and wood is combustible. So, what was the change in that scenario? Why is wood now returning to the fields of architecture and construction with an extraordinary dynamics?
I must add here just a quick note to avoid misunderstandings. When I mention wood in Architecture and construction, I am thinking mainly about wood’s structural and integral solutions. We all know that even a country like Portugal, where full wood construction is not part of the building culture, wood as a partial solution always had an important role.
Let’s continue to answer the previous question. Four main factors can be pointed out to justify the renaissance of wood: first, the technological evolution of wood products, secondly the setting of an advanced framework of standards, thirdly the updating of fire safety regulations, and the fourth factor consists in the attraction human beings, especially Architects, feel about wood. Wood is considered beautiful, warm, and always unique. The invention and refining of engineered wood have provided a new range of products such as laminated timber and boards that can perform better than solid wood in aspects such as strength and durability. Construction wood standards were based on a greater knowledge of the factors that affect its integrity, so they define the conditions and limits for its good and safe use. Fire safety regulations have recently become more pragmatic, objectively considering the behavior of wood and recognizing the existence of new means to combat the fire.
On the architects’ side, because they are responsible for the design of the Human life’s shelters, there is a will to minimize the impact of construction on the environment. Architects know they should use renewable materials. Thus, the architectural rediscovery of wood is justified, not only by its splendid aesthetic qualities but also by its ethical role, that is, by its good environmental behavior. There is an important contribution wood can do to reduce global energy consumption and Carbon emissions.
Even without considering numbers and calculations, which sometimes lead to contradictory and convenient or inconvenient results, depending on the side we are on, let’s look at the sources of the raw materials: Let’s compare an iron mine, a quarry, and a forest. Which one can we regenerate with fewer means and less impact? Let’s compare now a metallurgical company with a sawmill, or an ornamental stone processing plant with a carpentry shop. Which will require more energy to transform the raw materials? The answers seem obvious.
These arguments might be convincing… until we think about the forest’s problem. To build with wood we will have to cut trees. And we know that trees and forests are essential to maintaining the planet’s balance. Trees, as we know from schooldays, absorb Carbon and provide us Oxygen, retain water and balance their cycle, protect soil’s erosion, and are supports of biodiversity. All their qualities seem to help us understand that it is a crime to cut them down. We are aware, for example, of the tragedy that is taking place in tropical forests, where wild deforestation is almost impossible to stop.
It seems that we have to observe a bit in detail what is going on in the forest. The forest, as Joachim Radkau says in his book “Wood – A History”, has been the subject of a triangle of tense relations between the forest sector, the timber processing industries and the environmental movements. In the first vertex, the forest owners want to get the maximum profit, provided that the forest can be perpetuated as a source of revenue. The timber processing industries could, in principle, be seen as the “bad guy” since their goal is to extract the maximum amount of wood at the lowest price. Environmental protection agencies, defending the public point of view, would fight for forest’s conservation by combating the cutting of trees and the actions of the other two vertices. But urged to look at the planet on a global scale, when they are forced to find alternatives to the “oil economy”, they end up finding virtues in the responsible use of the forest. This was the case, for example, in Germany in 2004 with the Charta für Holz (updated in 2017), encouraging wood consumption in construction as a means of climate protection. This “Charter for Wood” was supported by all sectors and interests, from the Green Party to the wood industries.
We should remember that the word sustainability was used first in the context of forest management. As early as the fourteenth century in France, “soutenir” was used in forest protection laws. Later in 1713 Hans Carl von Calowitz came up with the idea of “Nachhaltigkeit” to refer to forests’ sustainable uses. Thus, forest owners and producers, proponents of the “economic forest”, have always had concerns about its renewal. On the other hand, there has always been a dangerous temptation to opt for rationalization measures, which are not always innocuous. There is, for example, the tendency to seek fast-growing species that allow for a greater number of rotations, but which sometimes lead to monocultures and to the weakening of biodiversity. As for the processing timber industries, they could be divided into two fields. On the one hand would be those in which the structural and aesthetic quality of the wood is not relevant for the produced products, as is the case of pulp and paper industries and of building materials based on wood particles and fibers. On the other side, we would find industries where the architectural, visual and structural quality of the wood is very important. These ones could perform a relevant role in the demand for higher quality products, thus helping to curb the low-cost vision of the forest, which is the prevailing vision in Portugal.
Environmental agencies will, of course, have an important place in the fight for a sustainable forest, in particular through the pressure they can put on for the implementation and improvement of forest certification systems (as FSC and PEFC). Besides pressuring for good forest regulations, their mission includes the information about the disadvantages of low-value monocultures and the benefits of biodiversity conservation. The remarkable role that Quercus, the National Association for Nature Conservation, has been playing in Portugal must be noted here as an example of this kind of public service.
Architects have an important role as allies of the environmentalist vertex. This alliance stems, as mentioned, from the fact that a “wood economy” is less harmful than the “steel and concrete economies”. Let us not forget that the impact of construction on the environment is gigantic. Around 50% of the world’s energy consumption and 50% of resources consumption is due to the construction sector. Architects will also be able to take advantage of the privileged relationship with the timber industries, that should be asked to offer more qualified wood products. The relationship with forest producers and owners, although less direct, may have two faces. Architects can act, on one side as a booster and on the other side a regulator. On the one hand, architects by using timber products can contribute to raising forests value. On the other hand, they are in a position of requiring forest-certification of the wood products used in construction.
Volunteer with Habitat for Humanity in Winnipeg, Canada. Photo Habitat for Humanity Manitoba.
We can conclude that the use of wood by Architects not only can be logical but can also be feasible. But for the Portuguese Architects, there is an additional problem. An architectural approach that claims to be environmentally responsible should not be limited to the use of renewable building materials. All sustainability manuals state that the materials chosen for construction should be of local origin. Can we then consider that it is irresponsible for an architect in Portugal to prescribe wood products from Canada, Germany, Austria or Sweden?
As it is almost impossible to find Portuguese wood for structures, it seems irrational to choose wood as a structural option. Despite the huge forest area (35%) of Portuguese territory, forest owners see it as a supplier of low-value products, where wood quality is not an important factor. This is one of the reasons why the forest is abandoned, with the tragic consequences we all know. Timber industries are mainly specialized in the production of products that require “low cost” raw materials and thus the criterion of planting becomes the growth rate of forest species. Environmentalists can not fight against this logic and Architects do not even enter the fight. With some remarkable exceptions, they surrender to the heavy logic of concrete and steel. Everyone can legitimately say that there is a hard to break “vicious cycle”. The guilty party will always be the business partner, who either does not demand wood or does not offer wood. If this is the situation, should we give up the idea of building wood in Portugal?
Assuming we agree on the benefits of replacing concrete and steel with wood, the final argument for its use in construction in Portugal will be precisely the need to break the toxic “vicious cycle.” If we start using wood, even if it is imported, the national market begins to feel pressured. The logic of the chain reaction can work. Imagine that architects begin to prescribe wood products. The domestic industry might begin to think of implementing more qualified products to compete with imported products. Forest owners and producers, feeling pressured by the timber industry, will consider a review of their “low-cost” strategy, promoting, for example, the planting of species of higher quality and greater economic value. The forest will slowly begin to be transformed into a more valuable and more beautiful landscape. Of course, this scenario can take years to be achieved. But it is the vision, even if distant, of this scenario that allows us to answer the initial question: Why should we build with wood? Because we know that all the choices we make today will have an impact on the generations that follow us. Because it is necessary to break the “vicious cycle”. Because it is our responsibility, the responsibility of Portuguese architects, the responsibility of forest owners, the responsibility of timber processing industries and it is the responsibility of the people in general, to make the choice between immobility and action.