Project contact is Hongmei Gu at the Forest Products Laboratory
The FPL team is in charge of developing a full comparative LCA study for three multiple-story mass timber buildings and their concrete alternatives in the U.S. Northeast region, with Boston as the point location. Using these three comparative LCAs, this research will determine the GHG emissions reduction potential from mass timber use in the building sector for the U.S. region. This may increase potential for growth in wood utilization, timber harvest, and forest management practices through the market demands.
With advances in wood product development and building code acceptance, mass timber structural systems have become viable alternatives to steel and concrete structural systems (Post 2015). These mass timber systems have environmental benefits, such as carbon sequestration ability and lower greenhouse gas emissions than steel and concrete systems. How can mass timber materials such as cross-laminated timber (CLT) reduce the environmental impacts of buildings, and how certain is this reduction? In order to truly answer this question, environmental impact assessments of CLT and other wood materials must first address variation and uncertainty in forest management and biogenic carbon accounting.
EBD was first developed by the Athena Sustainable Materials Institute. An EBD is a summary report of the comprehensive environmental footprint data for a building and declares life-cycle impacts according to a standardized format. It is a statement of performance and is publicly disclosed, similar to a nutrition label on a food package. The intent of the document is to present results as transparently and concisely as possible.
Athena’s EBDs are compliant with the European standard EN 15978, a whole-building LCA standard that is intended to support decision-making and documentation around the assessment of environmental performance of buildings. The Design Building would be the fourth building to be assessed as part of Athena’s EBD initiative and the first located in the United States.
Lend Lease is constructing a new residential building using cross laminated timber (CLT). This
material is a relatively new building material in Australia, which has found increased use in multi-story residential and commercial buildings, particularly in Europe. The Centre for Design (CfD), School of Architecture and Design, RMIT University was commissioned by Lend Lease through Forest and Wood Products Australia (FWPA), to investigate the environmental performance associated with the production of the materials, along with HVAC and lighting systems, and associated operation and end-of-life of this novel building, using a life cycle approach.
Life Cycle Assessment (LCA) has been used as the core method for determining the potential
environmental impacts of the products considered. LCA has been applied in accordance with ISO
14040:2006. Data on the building materials quantities and construction details were supplied by Lend Lease, background life cycle inventory data was gathered from Australian (AUPLCI) and European (Ecoinvent) databases. Data on cross laminated timber was provided by the manufacturer in an Environmental Product Declaration (EPD). Annual operational energy use for the Forté and the reference buildings were calculated using the dynamic building energy simulation software tool ApacheSim. The simulation results for residential spaces were validated against results from an Accurate assessment.
Katerra is a start-up construction company that has developed a vertically integrated cross-laminated timber (CLT) manufacturing supply chain and facility. Katerra commissioned the Carbon Leadership Forum (CLF) and the Center for International Trade in Forest Products (CINTRAFOR) at the University of Washington to perform a life cycle assessment (LCA) study to understand the environmental impacts and opportunities for impact reduction in Katerra’s CLT supply chain and manufacturing process. CINTRAFOR performed an LCA of the CLT supply chain and production process while the CLF performed a whole building LCA of a new building that used CLT produced at Katerra’s CLT facility.