Production, innovation, research and carbon footprint
The construction industry is responsible for 30% of CO2 emissions, so it’s urgent to lower that number. Meanwhile, in terms of capture, wood is the only construction material that absorbs CO2 instead of emitting it.
Also, wood-based construction solutions have a great design flexibility, allowing to combine different aesthetic, functional and adaptive solutions.
Chile is a forest and timber country par excellence but, paradoxically, in constructions in our country, concrete is the most used material. What are the opportunities of wood in the present and future of constructions?
Francisco Lozano, head of innovation from Arauco, assured that Chile has a big opportunity in the use of wood for the construction of houses, buildings, architectural works, mining camps and schools, due to the presence of a developed forestry sector and the advance achieved in order to make wood-based construction a reality.
“Sustainable construction with wooden structures has progressed in Chile, today reaching 18% of households, which is a high percentage, if we consider that apartment buildings are majority in Chile. We have the challenge to double this number in the next 10 years,” said Lozano.
On the same line, Eduardo Hernández, head of wood-forest operations from CMPC Celulosa, mentioned that wood has a huge potential for construction in Chile and the world; in fact, it has been used for construction for thousands of years and, in some countries, it remains one of the most used materials.
“In Chile, unfortunately, less than 20% of households are built with wooden structures; in the United States and Canada, however, the number is closer to 90%. This gap accounts for the great potential of increasing its use. All this, not considering that Chile is also a major wood producer, anually producing more than 8 million cubic metres of sawn timber and more than 3 million cubic metres of boards that can be used in a very competitive way in many types of buildings,” said the manager from CMPC.
Today, added Fernández, CMPC’s corporate building in Los Ángeles is an example that we can build in Chile with the latest technologies and a high standard for wood construction, which could be perfectly applied in kindergartens, schools, hospitals, hotels and public services.
Meanwhile, José Catalán, head of innovation from MASISA, affirmed that Chile has important advantages, like raw material availability, given that the country has developed a relevant forest industry at a global level. “On the other side, the country’s geographic diversity determines different requirements for thermal insulation, an issue that the supplementary use of wood with other materials can solve. Finally, Chilean professional building quality, given our seismic reality, is quite good, which should be used to introduce wood as a structural building material,” explained Catalán.
Production challenges
Arauco’s Francisco Lozano pointed that construction in the world faces two big challenges: productivity and sustainability, hence industrialisation is fundamental alongside the use of renewable materials, where wood has a big opportunity, given that it’s a good material for industrialisation and is esentially renewable.
“New technologies will definitely help productivity in construction, BIM technologies, industrialisation, among others, will contribute in this line. Today in Chile we are seeing advance going in line with 4.0 construction, examples such as Baumax and E2E, new companies that have integrated cutting-edge technology in industralisation. There are also companies present in the industralisation market, especially in southern Chile,” mentioned Lozano.
Likewise, Eduardo Hernández from CMPC Celulosa, mentioned that wood is an organic material with appropriate features for its use as building material, so versatile that it would even help build a house where practically all its materials are wood applications, which is almost impossible to do with other materials.
Hernández added that wood has a natural resistance to electrical conductivity. It’s an easy material to work on and has a high fire resistance due to its low thermal conductivity. Its resistance and dimensions are neither significantly affected by heat, which brings stability to the finished building.
“Wood’s acoustic features make it ideal to reduce echo in spaces, it absorbs sound instead of reflecting or amplifiying it and can help to significantly reduce noise levels for higher comfort. Finally, due to the wide variety of available species, wood has an incredible variety of aesthetic choices,” reaffirmed the manager from CMPC Celulosa.
From MASISA, its head of innovation, José Catalán, emphasised that, according to publications, some of the goods or features from wood is its high resistance, flexibility, capacity to isolate noise vibrations and heat, especially opposite alternative main materials such as steel, bricks and concrete.
“Wood is a combustible material as opposed to steel, bricks and concrete, which are fire-resistant. However, it depends on the household’s building quality its capacity to resist fire. The urbanisation of population and inertia in the use of bricks and concrete by construction professionals are the reasons I identify for the lower use of wood these days, an issue that should be reverted,” he stipulated.
Research and academia
For Francisca Lorenzini, architect, head of innovation at Madera21 from the Corporation for Wood (CORMA), wood has 2 advantages in the construction industry. On one side, it’s a sustainable material. Trees absorb CO2 during their growth, and keep it in all throughout their useful life. It’s also a renewable resource, which is replanted once harvested.
“It’s an easily industrialisable material, which allows to have constructions quciker, with less waste, making construction industry more productive and sustainable,” she emphasised.
Felipe Victorero, subdirector of transference from the UC Centre of Innovation in Wood, said that Chile is one of the main wood producers in the world, so it has a huge timber potential.
Nonetheless, he warned, we don’t use this material in national production and we depend on other materials with a higher carbon footprint, higher added energy and even imported from other countries, which makes our construction not so sustainable. Here is why Chilean wood represents a unique opportunity to develop construction around sustainability, mentioned the UC specialist.
“As a country we could develop buildings much more environmental friendly, with low environmental impact, low added energy and, especially, low carbon footprint. That’s where we have to boost our timber industry and effectively make new products around wood and new solutions accompained by construction,” added Victorero.
Florian Schepp, architect and professor at the Faculty of Architecture and Arts from Universidad del Desarrollo, mentioned that the potential for the use of wood in Chile is high, mainly in the southern central part of the country, for the sole existence of this renewable resource locally available.
“For economical and environmental purposes, wood should have more visible competitive advantages in relation to other materials, so its use should increase in mid and long terms. This must be, however, associated to the provision of high quality supplies, and shape and dimension stability, very necessary characteristics in an each time more demanding construction industry,” stipulated the architect from UDD.
Features
Francisca Lorenzini mentioned that wood itself has very interesting essential features, for example, its high fire resistance and good thermal performance. “These are features from wood itself, for example, by comparing one cubic metre of timber to one metre cubic metre of another building material. This would be applied for a solution such as CLT (cross laminated timber), which is 100% made of wood.”
“For example, light wooden building solutions (such as frame system), allow a higher oscillation in the presence of seisms without collapsing the structures. If we talk about fire or thermal insulation, this can be solved by increasing the volume of timber (because it performs well in these fields by itself) or making mixed solutions in frame with fire-resistant sheets and thermal insulation,” summarised the architect from CORMA’s Madera21.
Efficiency
Florian Schepp, architect and professor from UDD, said that wood construction in general allows the incorporation of thermal insulation among structural elements, which eases meeting or exceeding obligatory thermal requirements.
“Wood also has higher thermal resistance than other structural materials, so events of thermal bridges in building performance is lower. Another advantage from wood as building solution is its lower contained energy in relation to other materials. Contained energy is the one necessary to produce and supply the product so, from this perspective, for being a ‘local’ material and low in energy intensity during production, wood has a low quantity of contained energy,” mentioned Schepp.
Francisca Lorenzini, meanwhile, affirmed that there are two possibilities to tackle the great urgency of climate change: reducing emissions and capturing CO2. Construction industry is responsible for about 30% of CO2 emissions and it’s really urgent to lower this number. In terms of capture, wood is the only building material that absorbs CO2 instead of emitting it, she affirmed.
“If we add industrialisation in the building stage to all this, allowing to reduce waste, particulate material, and we add an appropriate design of building systems that allow to make environmental comfort in buildings in the usage stage, we have a unique opportunity to reduce CO2 emissions in the construction industry,” added the architect from CORMA’s Madera21.
Under the same prism, Felipe Victorero, subdirector of transference from the UC Centre of Innovation in Wood, assured it is a very fine material with very good features regarding insulation.
“Wood itself is made of many cavities, just like a tree, when it’s growing, which has many conduits that help transport fluids and elements that keep it alive; once it’s logged and sawn in pieces, wood retains these same features.”
These same cavities that previously transported liquids, explained Victorero, are currently air chambers kept into the material, which makes soundwave or heat transmission reduced and bringing good insulation. “Also, as the tree is flexible to the wind, so is wood in its structure, hence helping to absorb seismic movements very easily.”
Finally, the UC researcher reaffirmed that construction industry is one of the main responsible for greenhouse gas emissions and energy consumption on the planet and Chile is not the exception. Between 20 to 30% of the annually required energy goes around construction.
“That is where wood brings an unbeatable opportunity with respect to other materials; wood is a much more isulating material than concrete and steel, from a themic point of view; in fact, it’s less conductive and allows better heat conservation inside the structure, it reduces energy requirements for heating and, at the same time, associated emissions; in other words, unnecessary heating.”
International experience
Francisco Lozano, head of innovation from Arauco, mentioned that there are many countries building with wooden structures today.
“In this line, Europe and Japan are the most advanced, followed by Canada, the United States, New Zealand and Australia. We are progressing and we are being recognised; one sign is Chile’s allocation as world base for the World Conference on Timber Engineering, to be held in August 2020. It’s an honor to be confirmed as base of this important conference; it shows that we are progressing in this line.”
Today we see, highlighted Lozano, there is a worldwide trend towards a more sustainable construction and, in this line, wood comes as the only material to be used at a large scale.
Eduardo Hernández, head of wood-forest operations from CMPC Celulosa, affirmed that there are countries with a long tradition in building with wooden structures, such as the United States, Canada, Australia, New Zealand, Japan and parts of South East Asia.
In earlier times, he descirbed, all wooden buildings were built in place, but now with new engineered wood products (EWP), there is more prefabricated building out of site, existing modular kits that bring more flexibility and speed in construction.
“Even if there are modular prefabricated buildings offering a wide variety of opportunities. This technology has allowed the construction of 10-story buildings in America within just 12 weeks,” highlighted Hernández.
José Catalán, head of innovation from MASISA, agreed on America as a typical case where wood has a main role in construction, partly due to the do-it-yourself building capacity in the population, so, in this sense, wood is a much more friendly material for people to work on.
“I think the worldwide trend is to revalue wood as a structural building material, but it will still be a complement to steel and concrete.”
José Manuel Rebolledo, CEO of CONAF
“According to the country’s progress towards carbon neutrality, it’s very likely for the use of wood to become more relevant.”
What are the potentials for Chile to use wood for the construction households, cultural centres, buildings or other types of construction?
They’re important and significant, as Chile has vast extensions of forest plantations whose wood is suitable for different uses in construction, mainly species like the radiata pine. Also, the country has vast extensions of native forest susceptible to be used in a sustainable way, a resource composed by species that bring high quality levels for different constructive uses.
How does wood behave when facing a fire or a seism? Is it true that houses burn down quicker than other materials?
Wood has a huge capacity to absorb energy and resist impact charges, thus making it an excellent material for building in seismic zones. Regarding its capacity to resist action by fire, what’s important is the relation to the structure’s time of stability during a fire, which varies among types of wood: 0.8 mm/minute for conifers and 0.5-0.77 mm/minute for angiosperms.
Wood, in the least favourable case, has a surface loss of 0.55 mm/minute, remaining stable until a large part of its section is not burnt.
Something that doesn’t happen on steel structures which colapse when reaching their melting temperature (at around 400°C it loses 15-25% of its strength and, at 800°C, it loses its viable compressive strength) nor in concrete which, after the evaporation of surface interstitial water and the Spallina effect (at around 100-150°C), water produces covering loss by pressure and leaves armature brought to light, whose strength is lost for being made of steel.
Southern Chile is where we can spot more wooden constructions. What are the reasons why wooden construction stopped in our country?
In general terms, wooden construction levels were significantly reduced, basically because, by the time it was done, the country’s seismic characteristics weren’t appropriately considered and this fine material was replaced by concrete and brickwork, methods with a dominant position in the construction industry. Nowadays, wood is used for construction preferably at coastal areas, southernmost regions and, to a lesser extent, social housing.
What is the level of research, innovation and development for wooden construction?
Basically, what has been achieved through activities done by Chilean universities, highlighting UC’s Centre of Innovation in Wood (CIF), which executed the Torre Experimental Peñuelas project in 2018, requested by the Ministry of Housing and Urban Planning.
Has water scarcity been measured?
Chile is in an interesting process of awareness in relation to the effects of the reduction in precipitations in water supply, and its consequences on different productive processes that use it as a basic supply, including forestry. As a result, this issue has a main place in the works of the sector today, and is an active part in the agenda of the sectorial instances of reflection, as is the Forestry Policy Council.
What is your forecast in terms of the intensive use of wood in mid and long terms?
According to the country progress towards carbon neutrality, it’s very likely for the use of wood in an intensive way to become more relevant, for what it means to the carbon fixation process. The concrete challenge in this matter is to surpass the almost 20% of contemporary use of wood in construction.