Michigan State University (MSU) will develop a construction time and cost estimating tool for the use of cross laminated timber (CLT) in commercial building construction. This responds to a significant barrier to adopting such buildings among the architecture, engineering, and construction (AEC) industry, which has been reported since 2014. Despite broad agreement that first costs (and by extension time) and life cycle costs are an important facet of CLT buildings, over one third of architects were uncertain about this topic. Nine out of ten architects also listed costs and cost information as a significant barrier. This project will expand wood products markets by addressing this significant AEC industry barrier, and as a result, encourage more designers and constructors to specify CLT in their buildings. The project includes the development of a web-based predictive cost and time tool; this is quite common during the conceptual design stage, and as such, these tools exist for steels and concrete buildings, yet very little information exists for CLT. The team will also develop up to 20 CLT building case studies, with a focus on as-built costs, life cycle costs (building maintenance, energy, and carbon), construction time, and green building certification. These cases will be used to develop continuing education training modules for designers and constructors. Finally, in an attempt to motivate current students to become more knowledgeable about CLT, MSU will sponsor a 4- and 2-year CLT construction management competition. We expect these efforts to reach over 300 designers and constructors, and up to 75 AEC students.
Cross-laminated timbers (CLTs) are strong and lightweight structural building materials. CLTs are made from renewable wood resources and have significant economic potential as a new value-added product for the United States. However, market penetration has been obstructed by product affordability and lack of availability for use. Previous studies and projects have surveyed opinions of designers and contractors about the adoption of CLTs. No previous study was found that surveyed cost estimators, who serve the essential function of creating economic comparisons of alternative materials in commercial construction. CLTs are not included in these current cost estimation tools and software packages which may be limiting the potential use of CLT in construction.
The purpose of this study was to discover if cost estimation is being used to make structural decisions potentially affecting the marketability of CLT use in construction and building design because of the ability to estimate CLTs adequately. Through the use of a survey, the re-designing of a building, and discussions with subject matter experts, this study examined the knowledge level of cross-laminated timbers of under-surveyed building construction professions and the relationship between cost estimation and structural material choices. Their responses are demonstrating the need for better cost estimation tools for cross-laminated timbers such as inclusion in the Construction Specifications Institute's classification systems in order for CLTs to become a more competitive product. The study concluded that cost estimation is important for CLT market development, because it is being used extensively in the construction industry.