One of the most recent innovations in Engineered Wood Products is Cross-Laminated Timber (CLT). The system is based on the use of multi-layered panels made from solid wood boards glued together, with the grain direction of successive layers placed at 90° angles. The cross-laminated configuration improves rigidity, dimensional stability, and mechanical properties. Structurally, CLT offers performance comparable to concrete or steel, with panels suitable for use as walls, floors, roofs, and other applications. While CLT as a construction material has been successful in Europe for the past 20 years, and more recently has made inroads in the Australian and Canadian markets, it is not yet readily available in the United States. To better understand the market potential for CLT in the U.S., this study aims to assess the level of awareness, perceptions and willingness to adopt the system by U.S. professionals. To achieve these objectives, (a) a series of 10 interviews were conducted to gather insights from national and international CLT experts; (b) a web-based survey to U.S. architecture firms was conducted to gather information about familiarity, perceptions, performance and likelihood to adopt the system in the near future; and (c) a multi-family residential building project was designed to explore the architectural possibilities of the material.This study identified that the use of wood, a natural and renewable material, was the main advantage of CLT. Another important benefit of CLT over traditional construction systems is the dramatically shorter on-site construction time needed. CLT is a prefabricated system, thus reducing labor requirements, on-site waste, and accidents, all of which translates into significant cost reductions. The most commonly cited disadvantages of CLT were its acoustic and vibration performance. From the study it was found that the level of awareness about CLT is low among U.S. architects. Building Code compatibility, availability in the domestic market and cost were mentioned as the main barriers to the implementation of the system in the U.S. Cross-Laminated Timber appears to be a cost-competitive alternative to concrete structures, especially for buildings over six stories high. Architects seem to be willing to adopt CLT for their near-future projects, especially for multi-family, commercial, and recreational buildings. Importantly, this willingness to adopt CLT was found to be positively correlated to the level of awareness with the system. Results show that diffusion of knowledge about CLT and the role of early adopters will be essential for the successful introduction of this new building technology into the U.S. market. The preliminary design created as part of this study allowed demonstrating the structural capabilities of CLT, by maximizing the spans between structural elements achieving open and fluid living spaces. CLT also enabled the design of wide terraces and the inclusion of window openings on outside walls without compromising the structural integrity of the CLT elements.
In the 20 years since its invention in Europe, cross-laminated timber (CLT) has become a widely used construction material in parts of the old continent and has started to attract global attention. CLT possesses numerous advantages as a construction material, including its superior structural and environmental performance, as well as the speed and efficiency with which CLT buildings can be erected. In this study, European engineers were surveyed to learn about their current level of awareness of CLT, the major barriers to CLT adoption, and about the most pressing research needs to advance the use of CLT as a construction material. The study used a web-based survey with a convenience sample of 93 different kinds of timber and civil engineers and/or researchers, most of which belong to a European CLT research network. Results showed that participants think that, in general, the level of awareness about CLT among developers, construction managers, engineers, architects, and construction managers, is low. The majority of perceived barriers for CLT adoption involved its building code compatibility and the availability of technical information. The most pressing research needs for CLT development, according to respondents, are in the areas of structural performance and connections, moisture performance, and market research.
Cross-Laminated Timber (CLT) is emerging as a promising building system that could help revitalize a dwindling forest sector. However, little research has been conducted about CLT, particularly in the marketing realm. Our paper helps bridge this gap. Specifically, we aim to identify research areas that are important to successfully advance CLT as a building material in North America. Our findings, based on a survey of experts, suggest that the level of awareness about CLT among building professionals in general is low. However, architects are considered knowledgeable about the product. Experts consider that the most important barriers to the adoption of CLT are(a) misperceptions held by building industry professionals about wood and CLT, (b) compatibility of building codes with CLT, and (c) the availability of technical information about CLT as a construction system. In terms of most pressing research areas for advancing CLT, experts consider that it is important to shed more light on its seismic and fire performance, and also on proper connectors and fasteners used in CLT-based construction.
Mass Timber Building Material in The U.S. Construction Industry: Determining the Existing Awareness Level, Construction-Related Challenges, and Recommendations to Increase its Current Acceptance Level
Timber has been considered as a promising building material because of its structural rigidity, environmental sustainability, and renewability nature. In Europe and Australia, timber materials have been used for many different types of construction such as residential, commercial, education, and industrial. However, in the U.S., the familiarity of timber products is gaining momentum. The construction practitioners are still reluctant to consider mass timber as a mainstream building material. A limited number of case study projects make it difficult for industry personnel to evaluate the actual construction feasibility of mass timber. As a result, a significant knowledge gap has been created that hindering the progress of mass timber material in the U.S. construction industry. To help solve the problem, this study aims to identify the existing awareness level among the U.S. building constructors regarding mass timber building materials. It further determines some of the major construction-related difficulties of mass timber buildings and recommendations overcome those difficulties to increase the acceptance of this material. The study performed a semi-structured questionnaire survey to carry out statistical analysis regarding mass timber building material. Analysis of descriptive statistics suggested that the level of awareness and involvement by the U.S. construction practitioners in mass timber building is still significantly low as 55% of the participants indicated no experience on mass timber building construction projects. Qualitative data analysis suggested that lack of experience in timber construction, poor coordination among the project parties, design-related difficulties, and high cost of mass timber panels are the biggest construction-related barriers to adopt this product. To overcome the existing difficulties, the study proposed an increasing number of timber building projects and manufacturing plants, effective early collaboration among the project parties, developing skilled workers, and a nation-wide promotion by the owners and the architects. The outcomes of this study will be helpful for the industry practitioners and the owners to adopt mass timber as a mainstream building material. The study will further increase the acceptance of this material in the U.S. construction industry.
