Abstract

first_pagesettingsOrder Article Reprints Open AccessArticle A Comparative Cradle-to-Gate Life Cycle Assessment of Mid-Rise Office Building Construction Alternatives: Laminated Timber or Reinforced Concrete by Adam B. Robertson 1,*,Frank C. F. Lam 2 andRaymond J. Cole 3 1 Canadian Wood Council, 400-99 Bank Street, Ottawa, ON K1P 6B9, Canada 2 Department of Wood Science, Faculty of Forestry, University of British Columbia, 2424 Main Mall, Vancouver, BC V6T 1Z4, Canada 3 School of Architecture and Landscape Architecture, University of British Columbia, 6333 Memorial Road, Vancouver, BC V6T 1Z2, Canada * Author to whom correspondence should be addressed. Buildings 2012, 2(3), 245-270; https://doi.org/10.3390/buildings2030245 Submission received: 23 April 2012 / Revised: 25 June 2012 / Accepted: 26 June 2012 / Published: 17 July 2012 Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract 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.