Achieving sustainable development requires the decoupling of economic growth from the use of non-renewable resources. This depends on industry adopting unconventional approaches to production. This research explores the root causes of barriers to the adoption of such approaches in the construction industry, and applies a behavioural model to assess whether companies are hindered by capability, opportunity or motivation.
The long history of lowest-cost tendering in construction has led to a path-dependent lock-in to conventional market-driven objectives of cost and risk reduction; it is suggested that locked-in companies lack the commercial opportunity and hence motivation, rather than the capability, to adopt approaches perceived to increase cost or risk. Such companies will therefore tend to resist unconventional approaches, restricting the physical opportunity for other project participants. This theory is explored in a case study of first adoptions of cross-laminated timber (CLT) in UK projects, using a survey and series of semi-structured interviews.
The case study found that project contexts created market niches. This provided designers, who were motivated to use CLT, the opportunity to promote its use in the project. CLT was seen as key to successful resolution of project constraints, thereby providing motivation to other project participants to adopt the material.
In recent years, timber has been considered as an alternative source of building material because of its sustainability and design efficiency. However, the cost competitiveness of timber buildings is still under study due to the lack of available cost information. This paper presents a comprehensive cost comparative analysis of a mass timber building mainly developed with cross-laminated timber (CLT). The actual construction cost of the project is compared with the modeled cost of the same building designed as a concrete option. The result shows that the construction cost of timber building is 6.43% higher than the modeled concrete building. The study further investigated the change orders associated with the project and found that the total cost of change orders contributed 5.62% to the final construction cost of mass timber building. The study is helpful to provide insight into the construction cost of typical mass timber buildings. It also can be used as a guide for the project owners to make decisions regarding their initial investments on a mass timber project.
The study laid out in this report aims to build on the lessons learned from around the globe and
in BC to promote and facilitate the deployment of BIM and DfMA in the context of mass timber
construction. The study’s objectives were to:
1. Explore BIM tools and software platforms that support collaboration and optimization of
design solutions as well as enable seamless exchange of information in the context of
DfMA of mass-timber solutions.
2. Investigate the potential impact of the use of BIM tools and software platforms on
project and team outcomes in the context of mass-timber construction.
3. Investigate how the modeling process can be streamlined to minimize waste and
optimize the DfMA process in the context of mass-timber construction.
4. Investigate the readiness of manufacturers and installer/assemblers to supply BIM data
for products and systems.
5. Propose recommendations to position the supply chain to design, manufacture and
assemble mass-timber structures.
6. Propose recommendations that identify future training requirements for BIM enabled
DfMA in the context of mass-timber construction.
Classifications of volatile products that may pose health and comfort risks to occupants tend to be restricted by current regulations. It seems important to sample air from concrete, wood and steel buildings to measure the compounds present. Ideally, measurements at different time intervals could be considered to qualify and quantify contaminant dispersion dynamics over time. The project aims to identify a possible advantage of wood construction in the face of air quality, to identify the main contaminants (quantity and toxicity) and to propose sampling and measurement techniques adapted to the building environment.
Cross-Laminated Timber (CLT) is an innovative structural system based on the use of large-format, multilayered panels made from solid wood boards glued together, and layers at 90 degrees. This cross-laminated configuration translates into panels that are monolithic, stable, and experience minor shrinkage, which allows them to be used for the most diverse building applications, such as walls, floors and roofs. Developed in the early 1990 in Switzerland, as a way to reduce waste in sawmills, the system has been successful in Europe for the past 20 years, and more recently has made inroads into the Australian and North America markets. In the United States, the adoption of the system is still in its early stages. Recent research has shown that CLT could be cost-competitive as an alternative to concrete structures and for buildings over 6 stories high. The main goal of this study was to understand the market impediments to widespread adoption in the U.S. from an architecture firm’s point of view and compare the economic performance of CLT with that of traditional constructions systems, namely concrete and steel. A performing arts facility on the west coast of the US was evaluated as a case study. In order to accomplish this goal, a series of interviews with building professionals, as well as meetings with construction and estimating firms were conducted. Then an in depth analysis was performed to evaluate and compare the economic performance of the different construction systems in terms of cost of materials, labor, and speed of construction. This research addresses some of the key questions that must be answered if we are to understand the viability of a CLT market in the U.S.
On a number of occasions glued laminated timber breaks apart before the end of their service life. Examples in Germany (Frese M., Blaß H. J. ) and Denmark (Hansson, Larsen  ) show that this problem is real. In order to find the causes of the problem, extensive tests were conducted: 16 buildings with glued laminated timber were examined on the spot, calculations and laboratory work were carried out. These examinations told us that not only did the properties of the wooden material cause the damage, but the problems were also due to the wood used and the method of construction. In the calculations, the external load and residual stresses occurring in the glued laminated timber were included. Residual tensions in this timber were generated by climatic stresses and also due to the method of construction. These stresses also accumulated along with the stresses of the external load. Laboratory work was carried out to measure the delamination. We examined whether these analyses and calculations prove or disprove the results of the on- the- spot examinations.
This study illustrates the range of possible wood construction approaches for school buildings that are up to four storeys in height. As land values continue to rise, particularly in higher-density urban environments, schools with smaller footprints will become increasingly more necessary to satisfy enrollment demands. There are currently a number of planned new school projects throughout British Columbia that anticipate requiring either three-or four-storey buildings, and it is forecasted that the demand for school buildings of this size will continue to rise.
This study is closely related to the report Risk Analysis and Alternative Solution for Three- and Four-Storey Schools of Mass Timber and/or Wood-Frame Construction prepared by GHL Consultants, which explores the building code related considerations of wood construction for school buildings that are up to four storeys in height. Though wood construction offers a viable structural material option for these buildings, the British Columbia Building Code (BCBC 2018) currently limits schools comprised of wood construction to a maximum of two storeys, while also imposing limits on the overall floor area. As such, the reader is referred to the GHL report for further information regarding building code compliance (with a particular emphasis on fire protection) for wood school buildings.
This guide provides the directives needed for designers of tall wood buildings to produce their designs, plans and specifications. It has been developed to give them the information and general concepts required, based on the selected system. The elements and details required to comply with the guidelines in this document must be incorporated from a project’s initial design phase.
Part 1 – Guidelines contains several sections, including one that deals with basic conditions and describes the minimum general conditions applicable to any project for the construction of a wood building exceeding 6 storeys. The following sections contain special provisions that specify and complete the basic conditions.