The objective of this project was to quantify and compare the environmental impacts associated with alternative designs for a typical North American mid-rise office building. Two scenarios were considered; a traditional cast-in-place, reinforced concrete frame and a laminated timber hybrid design, which utilized engineered wood products (cross-laminated timber (CLT) and glulam). The boundary of the quantitative analysis was cradle-to-construction site gate and encompassed the structural support system and the building enclosure. Floor plans, elevations, material quantities, and structural loads associated with a five-storey concrete-framed building design were obtained from issued-for-construction drawings. A functionally equivalent, laminated timber hybrid design was conceived, based on Canadian Building Code requirements. Design values for locally produced CLT panels were established from in-house material testing. Primary data collected from a pilot-scale manufacturing facility was used to develop the life cycle inventory for CLT, whereas secondary sources were referenced for other construction materials. The TRACI characterization methodology was employed to translate inventory flows into impact indicators. The results indicated that the laminated timber building design offered a lower environmental impact in 10 of 11 assessment categories. The cradle-to-gate process energy was found to be nearly identical in both design scenarios (3.5 GJ/m2), whereas the cumulative embodied energy (feedstock plus process) of construction materials was estimated to be 8.2 and 4.6 GJ/m2 for the timber and concrete designs, respectively; which indicated an increased availability of readily accessible potential energy stored within the building materials of the timber alternative.
Sustainability and innovation are key components in the fight against climate change. Mass timber buildings have been gaining popularity due to the renewable nature of timber. Although research comparing mass timber buildings to more mainstream buildings such as steel is still in the early stages and therefore, limited. We are looking to determine the difference between carbon footprints of mass timber and traditional steel and concrete buildings. This is done with the intention of determining the sustainability and practicality of mass timber buildings.
The Nature Conservancy is leading a multi-institution collaboration to quantify the potential for innovative mass timber materials to support improved forest management, revitalize forest economies and mitigate greenhouse gas emissions. Life cycle assessments (LCAs) of engineered timber products such as glued laminated timber (glulam) and cross-laminated timber (CLT) in construction have highlighted their environmental advantages over conventional materials such as concrete and steel. However, there is little understanding of how developing new markets for such materials could support the wood product sector and the management of US forests. This applied research will assess in detail the potential impacts of large-scale growth in mass timber demand on wood product markets, timber harvest, forest management and climate change mitigation in key wood-producing regions across the USA and globally, as well as opportunities to leverage these markets to support US forest management and rural economies. The findings will be used to produce peer-reviewed publications and design a suite of targeted stakeholder engagement materials and programs, providing an objective, credible fact base to inform the design of policies and programs to maximize environmental and economic benefits of mass timber use for the forest sector.
As part of the CORRIM Phase I research, this study completed a full gate-to-gate life-cycle inventory for the production of glued-laminated timbers (glulam) produced in two regions of the United States—the Pacific Northwest (PNW) and Southeast (SE)...
More and more people live in cities. The building industry is responsible for 33% of waste production and is set to increase further to 50% in 2025. The energy efficiency is continuously increased, but the waste production at the end of life of a building is largely ignored. This design proposes a solution in the form of a zero-waste high-rise design. It uses only recyclable or renewable materials. Mass-timber is chosen as the main material as it is not only renewable and easily reusable, it is also a storage of CO2. The design reuses the foundation of existing buildings, and with the lightweight properties of mass-timber, increases the density on the location by building taller. The design is four times taller as the current buildings. To allow for sustainable densification, the design offers public and collective qualities. The building has been designed is such a way to be easily refitted during its life cycle or to be completely disassembled at the end of life.