Project contact is Pierre Blanchet at Université Laval
Several studies indicate that using wood from sustainable forest management in building construction both maintains or increases carbon sinks in the forest, temporarily captures carbon in buildings, and substitute more emitting materials or fuels. This strategy is interesting, but it is difficult to implement from a political point of view because its real benefits are complex to evaluate. There are several methods for evaluating the GHG impacts of a product over its entire life cycle, but there is no consensus on the method to be used to assess the impacts of GHGs from biogenic carbon - the carbon contained in living or dead biomass, such as wood. Many commonly used methods rely on simplifying assumptions that do not accurately assess the benefits that could accrue from increased use of wood products under construction. This PhD project will improve a promising method to evaluate the GHG impacts of biogenic carbon. Particular attention will be paid to the uncertainties of the method so that it provides all the information necessary for informed decision-making. The expected results could confirm that greater use of wood products reduces the environmental impacts of buildings, and that current methodologies are too simplified to inform policy making.
This research investigates a new structural system based on a central core of CLT (cross-laminated timber) panels to provide more useful multi-level timber buildings that are taller and with open floor areas. Because pinus radiata is a suitable timber for the manufacture of CLT panels, the system has the potential to add value...
Cross-laminated timber (CLT) is a large prefabricated solid engineering plank made of multiple layers of planks glued together and it is primarily used in structures such as the floors, walls, and roofs of buildings. ANSI/APA PRG 320 is the world recognized CLT lumber production standard, and the main raw material of CLT has always been softwood rather than hardwood. However, the bending strength, compressive strength, and shear strength of hardwood CLT lumber are stronger than softwood CLT lumber. The large and underutilized hardwood resources in central and southern Ontario provide a huge resource advantage for the hardwood CLT project. This article uses the Cost-Benefit Assessments model to assess the feasibility of investing in hardwood CLT plants in central and southern Ontario. The results show that the payback period of the hardwood CLT factory is 5 years, and the rate of return on investment of 10 years, 15 years, and 20 years are all-around 11%. This study could strengthen investor confidence and it also identifies the direction for the development of hardwood CLT plants in central and southern Ontario.
This report provides an overview of major changes occurred in the recent decade to design and construction of the building envelope of wood and wood-hybrid construction. It also covers some new or unique considerations required to improve building envelope performance, due to evolutions of structural systems, architectural design, energy efficiency requirements, or use of new materials. It primarily aims to help practicioners better understand wood-based building envelope systems to improve design and construction practices. The information provided should also be useful to the wood industry to better understand the demands for wood products in the market place. Gaps in research are identified and summarized at the end of this report.
Canadian Conference on Building Science and Technology
On tall wood buildings, mass timber elements including CLT, NLT, glulam, and other engineered
components absolutely need to be protected from excessive wetting during construction. This requirement precludes the use of many conventional cladding systems unless the building is fully hoarded during construction.
The building enclosure and façade of UBC Tallwood House consists of an innovative prefabricated steel stud rainscreen curtain-wall assembly that is pre-insulated, pre-clad, and has factory installed windows. Design of connections and air and water sealing of panel joints and interfaces was carefully considered given the tall wood structure they were designed to protect. While steel studs were utilized in the panelized structure, feasible curtain-wall designs were also developed and prototyped for wood-framing, CLT, and precast concrete as part of the project.
Looking ahead, there will continue to be innovation in design and construction of fast and durable facades for taller wood buildings. New prefabricated panel designs incorporating CLT panels and connection technologies from unitized curtainwall systems are already being developed for the “next tallest” wood buildings in North America.
Most office building construction relies on steel and concrete for mid-high rise office building applications. The primary goal of this thesis is to understand the implications of CLT and mass timber construction systems for mid-high rise office buildings in Seattle by developing a prototypical office building located on a specific site. This research thesis will focus on comparing this prototypical mass timber office building design to the same/similar design using industry standard construction materials for Seattle. The criteria for comparison will include code, cost, schedule and greenhouse gas emissions.
Project contact is Pierre Blanchet at Université Laval
This project will carry out a life cycle analysis of the main building envelopes for a typical building in commercial construction. Drawing on our design partners, the main systems and associated materials will be analyzed in a cradle-to-grave approach. The aim is to identify hot spots and indicate product development opportunities to reduce the environmental footprint of the envelope. Among the scenarios to be considered: light framing, CLT, curtain walls and all their possible variants, but also the non-biosourced systems commonly used. The comparison between the systems studied will be based on equivalent energy efficiency performance.