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.
The present paper is the first to conceptually assess the viability of mass timber construction (MTC) as an alternative construction material/method in Australia. It fulfills an identified need to examine an innovative construction process providing much needed information concerning the technologies current position and future disruption to traditional construction methods. A common tool used in business management studies, the PESTEL model, Political, Economic, Social, Technological, Environmental and Legal is employed to provide structure for a strategic analysis of the technology. Mass timber construction clearly demonstrates some advantages including cost savings, primarily in the reduction in on-site labour costs; a lower environmental impact and use of a renewable resource; and possibility of improved amenity and reduced running costs for owners and occupiers. The estimated market potential for MTC in Australia indicates that a local plant might be viable as the market grows, and warrants funding to underpin a full feasibility assessment.
The use of mass timber in high rise construction is an innovation. Mass timber construction has influential benefits including a lower overall construction time, a lower environmental impact, the use of renewable resource and an improved aesthetics. Despite the mentioned benefits, mass timber is not the traditional material for low to mid-rise commercial, institutional and residential construction in Canada. This is partially due to the need to explore the efficiency of mass timber construction relative to traditional construction. Detailed quantitative documentation of successful construction projects assists organisations planning mass timber high-rise projects by understanding and quantifying the advantages to ensure the viability of the construction process. This research project aims to understand the performance of mass-timber construction in the context of a construction manager, particularly the time saved due to completion of structural and envelope systems early. The case study chosen for this thesis is the tallest mass timber hybrid building in the world: Tallwood House. The research team studied the project in a macro-level perspective to investigate the building elements as single entities. Moreover, a micro-level study focuses on the performance of every level of the following elements: mass timber structure, envelope cladding systems and cross-laminated timber drywall encapsulation. The macro-level study investigates: (1) The production rate of the various building elements, (2) The coordination between structural trades to build a heavily pre-fabricated building using a single crane, and (3) The labor efforts per discipline. Moreover, the micro-level study investigates: (4) The variability of productivity of all levels, (5) A statistical investigation of three factors on cross-laminated timber installation, (6) Schedule reliability of preliminary planned schedule relative to the construction schedule (actual progress), (7) Earned value analysis, and (8) Planned percent complete to study the reliability of weekly work plans relative to construction schedules. All metrics were validated by the senior project manager through a discussion and confirmation of the inputs, findings and conclusions drawn. The claimed contribution of this research is an advanced state of knowledge about mass timber by exploring the efficiency of the construction process.
A research project, Wood and Wood-Hybrid Midrise Buildings, was undertaken to develop information to be used as the basis for alternative/acceptable solutions for mid-rise construction using wood structural elements. As part of this project, four large-scale fire experiments were conducted to evaluate the fire performance of two forms of encapsulated combustible structural wood systems, a lightweight wood-frame (LWF) system (2 experiments ) and a crosslaminated timber (CLT) system (1 experiment ). The fourth experiment  involved a test structure constructed using a steel frame system described below. Each experiment involved construction of a test set-up of an unsprinklered full-size apartment unit, intended to represent a portion of a mid-rise (e.g. six-storey) building.
This report provides the results of the test with an encapsulated LWF setup representing an apartment in a mid-rise (e.g. six-storey) building.
This monitoring study was initiated to collect performance data from a highly energy efficient, six-storey building located in the coastal climate of British Columbia. This work focuses on the following objectives by installing sensors during the construction:
· To provide information about the indoor environment of a highly energy efficient building
· To provide field data about the durability performance of an innovative high energy efficiency exterior wall solution for mid-rise wood-frame construction
· To provide information on the amounts of vertical movement in wood-frame exterior walls and interior walls below a roof/roof deck
A research project, Wood and Wood-Hybrid Midrise Buildings, was undertaken to develop information to be used as the basis for alternative/acceptable solutions for mid-rise construction using wood structural elements. The effectiveness of the encapsulation approach in limiting the involvement of wood structural materials in fires was demonstrated in this research project through bench-, intermediate- and full-scale fire experiments. These results for encapsulated lightweight wood-frame (LWF) systems and encapsulated cross-laminated timber (CLT) systems are documented in a series of reports [3, 4, 5, 6].
In addition to developing the encapsulation approach for protecting the wood structural materials to meet the above code intent, research was undertaken to examine standard fire resistance of encapsulated wood structural assemblies for use in mid-rise wood/timber buildings. One of the major differences between structural LWF assemblies used in mid-rise wood buildings (5-6 storeys) and low-rise wood buildings (= 4 stories) is the wall assemblies for the lower storeys. For mid-rise wood buildings, loadbearing wall assemblies on the lower storeys have to be designed to resist higher axial loads due to the self-weight of the upper storeys, which often result in the need for larger-size stud members and/or a greater number of studs, and higher lateral loads in case of seismic events or wind loads, which often requires the use of wood shear panels within the wall assembly. These wall assemblies very often will need to meet standard fire resistance requirements, and therefore, information regarding their standard fire-resistance ratings should be developed. This report documents the results of fullscale furnace tests conducted to develop standard fire-resistance ratings of encapsulated LWF assemblies for use in mid-rise applications.
With the introduction of 5 and 6-storey wood structures into the National Building Code of Canada 2015, it is important that guidance be provided to engineers to ensure that a reasonable design approach can be sought in the design of taller wood structures. The purpose of this technical paper is to compare various methods for calculating building...
This report was commissioned to review and formulate strategies for the accelerated uptake and
social acceptance of living in multi-storey cross-laminated timber (CLT)-constructed buildings in infill developments to: remove cultural barriers, meet the sustainability expectations of potential buyers and obtain a better understanding of how we can facilitate the rapid introduction of this innovative construction technology in Australia.
An extensive review of literature within the field was conducted to gather an overview of the
barriers that inhibit consumers, governments and industry in the uptake and acceptance of CLTconstructed buildings for infill development. Data was collected on CLT buildings worldwide, to build a comprehensive picture of multi-storey timber buildings using CLT-construction systems.
Wood-based mass-panels (WBMP) are emerging as an attractive construction product for large-scale residential and commercial construction. Australia is following the lead of Europe and North America with several recent projects being completed using predominately cross-laminated timber panels (CLT). These sawn timber-based panels offer some key advantages to the construction and sawmilling industry. However, veneer-based mass-panel (VBMP) systems could offer additional benefits including the more efficient use of the available forest resources to produce WBMPs that have equivalent to superior performance to CLT. Research to confirm the expected technical viability of veneer-based systems is required. VBMPs could provide a valuable contribution, alongside CLT, to the Australian timber products market.
Project contact is Craig Mitchell at Black Box Offsite Solutions
The study assesses the current state of the prefabrication industry in Canada and identifies key challenges and potential market opportunities in the sector for the increased use of mass timber. This analysis of the current state of the industry examines all forms of prefabrication, with a focus on wood (light wood frame and mass timber) where possible. A more detailed analysis focuses on future mass timber market opportunities in Canada and globally, including prefabricated timber building elements (i.e. structural components, retrofit components, etc.) and building typologies. Recommendations will inform policy decisions and other efforts required to support the further development and adoption of prefabricated timber buildings in Canada.