The history of timber construction stretches back as far as the Neolithic period, or potentially even earlier, when humans first began using wood to build shelters from the elements. The appearance of the first polished stone tools, such as knives and axes, then made wood handling more efficient and precise, increasing the thickness of wood sections and their resistance. Over the decades, the rustic appearance of these early constructions became increasingly orthogonal and clean, as a result of standardization, mass production, and the emergence of new styles and aesthetics.
Today we are experiencing another seminal moment within the evolution of timber. Nourished and strengthened by technological advances, new prefabrication systems, and a series of processes that increase its sustainability, safety, and efficiency, timber structures are popping up in the skylines of cities and in turn, is reconnecting our interior spaces with nature through the warmth, texture, and beauty of wood. Where will this path lead us? Below, we review 7 trends that suggest this progress is only set to continue, increasing both the capabilities and height of timber buildings in the years to come.
1. New Tools: Streamlining the Design and Construction Processes
Technological advances are changing the rules of the game as we know it and will only continue to expand the possibilities of building materials over the next few years. Tools and methodologies such as BIM, Virtual Reality, and 3D modeling and printing have begun to blur the border between design and construction, and are currently intertwined in a single major process of conceiving and developing new buildings.
The UBC Tallwood House at Brock Commons project, designed by Acton Ostry Architects & Hermann Kaufmann Architekten, utilized the joint work of multiple specialties —architecture, structural engineering, MEP engineering, contractors, consultants, suppliers, and others— through the BIM coordination and use of technologies provided by CadMakers, discussing, approving, and expediting the process through the review of three-dimensional models of the structure.
2. Cutting-edge Technology: Millimeter Manufacturing, Modular Systems, and New Materials
New technologies and systems are transforming the traditional job of carpenters, replacing their tools and processes with innovative machinery and assembly methods. CNC Machines, for example, allow beams and panels to be machined, in addition to generating custom components. They are operated by computational commands and allow the cutting, milling, and engraving of pieces of wood with a high level of precision through coordinate axes. These parts, then, can more effectively be joined through structural connectors, anchors, and fixing systems.
The speed and efficiency of construction with prefabricated and modular parts of precise dimensions have been enhanced by the emergence (or evolution) of mass timber. Among the most used include Cross-Laminated Timber (CLT), Glued-Laminated Timber (Glulam), Nail-Laminated Timber (NLT), and Dowel Laminated Timber (DLT) systems, as well as other interesting innovations such as Timber-Concrete Composite (TCC) and LVL Panels. All these advances make it possible to assemble buildings like a kit of parts, easily and quickly, increasing accuracy and dramatically reducing errors, labor, work time, and extra costs.
3. New Business Models: Integrating the Project Life Cycle in a Single Process
The total integration of design, engineering, materials and construction —and the new technologies that drive them more efficiently than ever —has led to the emergence of new business models, such as the End-to-End New Build service delivered by Katerra.
Focused on developers, the company assumes responsibility for the entire project life cycle, increasing its speed and efficiency by standardizing highly repeatable elements, taking advantage of the prefabrication of timber components, and using configurable kits and pre-installed mechanisms.
4. Changes in Building Codes: Breaking Myths and Expanding Possibilities
Important changes were made to the International Building Code when it comes to timber, set to take effect in 2021, including three new types of construction: buildings of up to 18 stories, with elements of mass timber covered with plaster (Type IV-A), buildings of up to 12 stories, with walls and ceilings of limited exposed mass timber (Type IV-B), and buildings of up to 9 stories, with 2 hours exposed fire-resistant mass timber (Type IV-C).
All these changes, which are in the process of being updated for 2021, are based on rigorous studies and testing, in addition to comprehensive consultation processes carried out by a committee formed by architects, structural engineers, specialists in building codes, and experts in fire protection. The next step is for regional building codes throughout the United States to adopt these changes.
5. Climate Action Policies: Governments Boost the Use of Timber
Global concerns to mitigate climate change have prompted some cities and governments to consider the embodied emissions of the materials we use to construct buildings, particularly the sum of all the energy required to extract, process, manufacture, transport, build, and maintain each material. With this consideration in mind, timber appears to be an attractive option, since according to many studies it can achieve less embodied and operational emissions in comparison to concrete and steel. In addition, the prefabrication of timber components with precision can deliver a highly efficient building envelope that improves insulation, saves on heating and cooling and minimizes thermal bridging.
The city of Vancouver, for example, is seeking to limit the emissions involved in the construction of new buildings by addressing them in the Greenest City 2020 strategic plan. In the near future, all developers will be required to report the embodied emissions for all chosen materials, with the objective of "reducing embodied carbon from new buildings and construction projects between now and 2030 by 40%."
6. Biophilic Design: Reconnecting Humans with the Natural
The use of timber in interior spaces can be one of the most direct ways to motivate a 'connection' between people and nature, especially when the timber maintains its most rustic and textured state. As we previously described, biophilic design seeks to improve the well-being of humans through direct contact with nature and organic forms, avoiding straight lines and 'aseptic' spaces. According to Nikos A. Salingaros and Michael W. Mehaffy, "we seek legibility and meaning in our environment, and we are repelled by environments that don't give us meaning." Thus, the rustic inconsistencies and variable tones of timber pieces can be integrated with indoor plants, living walls, colors, and other raw materials, enhancing the space with adequate ventilation and lighting as well.
This kind of biophilic design is not only being used in homes but especially in educational, hospital, and office spaces, thus improving the daily experience of people in their places of learning, healing, and work, reducing stress levels and promoting general comfort.
7. Ongoing Research on Timber's Performance is Expanding its Possibilities
The design of increasingly tall wood structures will continue to drive the development of research and experiments that will improve the accuracy of emergency responses, developing construction codes worldwide to become more comprehensive as well. Check out some recent studies here.
One case in point is fire performance. A team of fire experts from the U.S. Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) working alongside scientists from the U.S. Forest Products Laboratory put identically furnished, multistory, one-bedroom apartments constructed of exposed, partially exposed, and unexposed (protected) five-ply cross-laminated timber (CLT) through a series of rigorously monitored fire tests. The tests provided valuable data that was used in the development of code change proposals submitted by the ICC Ad Hoc Committee on Tall Wood Buildings (TWB) for the 2021 International Building Code.
Expect to see a growing body of research in the coming years that will help open up even more opportunities for mass timber construction and design.
All the signs seem to indicate that in 2020 and beyond, wood will take a leading role in the development of the cities that we will inhabit in the future. Timber has a potentially important role to play in helping architects, developers and urbanists address one of the greatest challenges of the next decade: the need to respond to the inevitable densification of our cities and deliver habitable spaces of high environmental quality without losing the inherent connection between humans and nature.
To read more about these trends and download a summary report visit Thinkwood.com