• Shaobo Liang
  • Hongmei Gu
  • Richard Bergman
  • Stephen S. Kelley


Cross laminated timber, environmental assessment, life cycle analysis, tall wood building


The US housing construction market consumes vast amounts of resources, with most structural elements derived from wood, a renewable and sustainable resource. The same cannot be said for all nonresidential or high-rise buildings, which are primarily made of concrete and steel. As part of continuous environmental improvement processes, building life-cycle assessment (LCA) is a useful tool to compare the environmental footprint of building structures. This study is a comparative LCA of an 8360-m2, 12-story mixed-us apartment/office building designed for Portland, OR, and constructed from mainly mass timber. The designed mass timber building had a relatively lightweight structural frame that used 1782 mof cross-laminated timber (CLT) and 557 m3 of glue-laminated timber (glulam) and associated materials, which replaced approximately 58% of concrete and 72% of rebar that would have been use in a conventional building. Compared with a similar concrete building, the mass timber building had 18%, 1% and 47% reduction in the impact categories of global warming, ozone depletion, and eutrophication, respectively, for the A1-A5 building LCA. The use of CLT and glulam materials substantially decreased the carbon footprint of the building, although it consumed more primary energy compared with a similar concrete building. The impacts for the mass timber building were affected by large amounts of gypsum board, which accounted for 16% of the total building mass. Both lowering the amount of gypsum and keeping the mass timber production close to the construction site could lower the overall environmental footprint of the mass timber building.


APA (2012) ANSI/APA PRG 320-2012 Standard for performance-rated cross-laminated timber. APA – The Engineered Wood Association, Tacoma, WA.

APA (2019) Case study: Mass timber has banks seeing green. (2 September 2019).

ASTM (2016) ASTM E2911: Practice for minimum criteria for comparing whole building life cycle assessments for use with building codes, standards, and rating systems. American Society for Testing and Materials, West Conshohocken, PA.

Bare J, Young D, Hopton M (2012) Tool for the reduction and assessment of chemical and other environmental impacts 2.1. STD Standard Operating Procedure (SOP) SOP No. S-10637-OP-1-0.

Berardi U (2017) A cross-country comparison of the building energy consumptions and their trends. Resour Conserv Recycl. 123:230-241.

Bowers T, Puettmann ME, Ganguly I, Eastin I (2017) Cradle-to-gate life-cycle impact analysis of glued-laminated (glulam) timber: Environmental impacts from glulam produced in the US Pacific northwest and southeast. For Prod J 67(5-6):368-380.

Bowick M (2015) Wood innovation and design centre Prince George, BC: An environmental building declaration according to EN 15978 standard. Athena Sustainable Materials Institute, Ottawa, ON, Canada. pp. 1-54.

Bowick M (2018) Athena Brock Commons Tallwood House, University of British Columbia: An environmental building declaration according to EN 15978 standard. Athena Sustainable Materials Institute, Ottawa, ON, Canada. pp. 1-55.

Breneman S, Richardson D (2019) Tall wood buildings and the 2021 IBC: Up to 18 stories of mass timber. WW-WSP-12. Wood Works. pp. 1-11.

Cadorel X, Crawford R (2018) Life cycle analysis of cross laminated timber in buildings: A review. Pages 107-114 in Engaging Architectural Science: Meeting the Challenges of Higher Density: 52nd International Conference of the Architectural Science Association and RMIT University, Melbourne, VIC, Australia.

Chen CX, Pierobon F, Ganguly I (2019) Life cycle assessment (LCA) of cross-laminated timber (CLT) produced in western Washington: The role of logistics and wood species mix. Sustainability 11:1278.

Connolly T, Loss C, Iqbal A, Tannert T (2018) Feasibility study of mass-timber cores for the UBC tall wood building. Buildings 8:98.

CSI (2016) MasterFormat 2016. Construction Specifications Institute (CSI), Alexandria, VA.

DATASMART 2019. LCI package (US-EI SimaPro® Library). (26 March 2020).

Durlinger B, Crossin E, Wong J (2013) Life cycle assessment of a cross laminated timber building. Forest & Wood Products Australia, Melbourne, VIC, Australia. ISBN: 978-1-921763-63-2, pp. 1-110.

EN (2011) EN 15978: Sustainability of construction works -Assessment of environmental performance of buildings -Calculation method. European Committee for Standardization, Brussels, Belgium.

Espinoza O, Buehlmann U (2018) Cross-laminated timber in the USA: Opportunity for hardwoods? Curr For Rep 4: 1-12.

FII (2016) Brock Commons Tallwood House. Forestry innovation investment (FII), naturally: Wood. (17 July 2019).

Finlayson G (2019) Personal communication. Athena Institute.

Grann B (2013) A comparative life cycle assessment of two multistory residential buildings: Cross-laminated timber vs. concrete slab and column with light gauge steel walls. FPInnovations Report, Vancouver, BC, Canada. pp. 1-121.

Gu H, Bergman R (2018) Life cycle assessment and environmental building declaration for the design building at the University of Massachusetts. General Technical Report FPL-GTR-255. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI. 71 pp.

Gustavsson L, Joelsson A, Sathre R (2010) Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building. Energy Build 42(2): 230-242.

Harris ZM, Milner S, Taylor G (2018) Biogenic carbon –Capture and sequestration. In Greenhouse Gas Balances of Bioenergy Systems, Chapter 5. Academic Press, Cambridge, MA. pp. 55-76.

Heppner J (2019) Personal communication. LEVER Architecture.

Huijbregts MA, Rombouts LJ, Hellweg S, Frischknecht R, Hendriks AJ, van de Meent D, Ragas AM, Reijnders L, Struijs J (2006) Is cumulative fossil energy demand a useful indicator for the environmental performance of products? Environ Sci Technol 40(3):641-648.

IPCC (2006) Guidelines for national greenhouse gas inventories. Institute for Global Environmental Strategies (IGES) for the IPCC, Kanagawa, Japan.

ISO (2006a) ISO 14040: Environmental management – Life cycle assessment – Principles and framework. International Organization for Standardization, Geneva, Switzerland.

ISO (2006b) ISO 14044: Environmental management – Life cycle assessment – Requirement and guidelines. International Organization for Standardization, Geneva, Switzerland.

Jones K, Stegemann J, Sykes J, Winslow P (2016) Adoption of unconventional approaches in construction: The case of cross-laminated timber. Constr Build Mater 125:690-702.

Karacabeyli B, Douglas B (2013) CLT Handbook, US edition. (17 July 2019).

Kelley S, Bergman R (2017) Potential for tall wood buildings to sequester carbon, support forest communities, and create new options for forest management. Forest Products Laboratory Research in Progress. (26 March 2020).

Kremer PD, Symmons MA (2015) Mass timber construction as an alternative to concrete and steel in the Australia building industry: A PESTEL evaluation of the potential. Int Wood Prod J 6(3):138-147.

Oregon BEST (2017) Advanced wood product manufacturing study for cross-laminated timber acceleration in Oregon & SW Washington. Technical Report. Oregon BEST, Portland, OR. pp. 1-111.

Perez-Garcia J, Lippke B, Briggs D, Wilson JB, Bowyer J, Meil J (2005) The environmental performance of renewable building materials in the context of residential construction. Wood Fiber Sci 37:3-17.

Pierobon F, Huang M, Simonen K, Ganguly I (2019) Environmental benefits of using hybrid CLT structure in midrise non-residential construction: An LCA based comparative case study in the US PNW. J Build Eng 26:100862.

Podesto L, Berneman S (2016) CLT research: Available and accessible to North American building designers. Wood Design Focus 26(1):3-7.

Ritter M, Skog K, Bergman R (2011) Science supporting the economic and environmental benefits of using wood and wood products in green building construction. General Technical Report FPL-GTR-206. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI. 9 pp.

Robertson AB, Lam FC, Cole R (2012) A comparative cradle-to-gate life cycle assessment of mid-rise office building construction alternatives: Laminated timber or reinforced concrete. Buildings 2:245-270.

Smith RE, Grifin G, Rice T, Hagehofer-Daniell B (2018) Mass timber: Evaluating construction performance. Architectural Engineering and Design Management 14(1-2): 127-138.

Tecchio P, Gregory J, Olivetti E, Ghattas R, Kirchain R (2018) Streamlining the life cycle assessment of buildings by structured under-specification and probabilistic triage. J Ind Ecol 23(1):268-279.

Walch F, Watts R (1923) Composite lumber. U.S. Patent 1,465,383.

Williamson T, Ross R (2016) Proceedings: Mass timber research workshop 2015. General Technical Report FPLGTR-241. U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison, WI. 364 pp





Research Contributions