INNOVATION July-August 2013

i ns igh t Towards Sustainable Design with Life Cycle Assessment Rob Sianchuk In collaboration with the APEGBC Sustainability Committee L ife cycle assessment (LCA) is a method used to structure quantitative evaluations of sustainability issues Structure of Life Cycle Assessment Methods Internationally, LCA methods follow the structure laid out by the standards

environmental impacts using a life cycle impact assessment method. The outcome of the calculation is a numerical indicator result typically stated on an equivalence basis. Below are examples of impact categories and indicator result units from the Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), an impact assessment method developed by the US Environmental Protection Agency (US EPA): • Global warming (CO 2 eq) • Ozone layer depletion (CFC -11 eq) • Acidification (kg SO 2 eq) • Eutrophication (kg N eq) • Smog (kg O 3 eq). 4. Interpretation –

associated with material and energy use by networks of processes that deliver goods and services (i.e., products). LCA is increasingly being integrated across industries as a key tool to measure and manage environmental impacts. The adoption of LCA is particularly prevalent in the North American construction industry, where green building standards, such as LEED, and product ecolabel standards, such as UL Environment, are providing professional recognition to building designers and product manufacturers for its use. These are particularly exciting developments for building designers who are increasingly under pressure to deliver high quality, high performance buildings on time and on budget. This uptake of LCA represents a critical opportunity for professionals in the construction industry to engage in the coordination of widespread environmental impact reduction strategies. The success of these efforts to reduce building and building-industry impacts will depend largely on the quality of the standards and professionals that will ultimately be carrying out LCA services in practice. Therefore, it is equally important to complement the development of the professional application of LCA with the availability of educational resources. It is critical for construction industry professionals, particularly those involved in building design, to inform themselves about LCA, as its widespread emergence into practice will create new opportunities to better coordinate and invest in impact reduction strategies. This article aims to provide clarity on the structure of LCA methods and an update on its integration into building design.

established in the ISO 14040-series. Within this series, ISO 14040, 14044 and 14025 are key to respectively establishing the structure of the LCA methodology, the requirements when carrying out an LCA study, and the due process involved in third-party verification of LCA studies. Specifically, ISO 14040 establishes that LCA studies need to follow a four-step methodology. 1. Goal and Scope definition – Defining the purpose of the study, and the parameters and assumptions that guide how the study will be

Goal & Scope definition

Evaluating the quality of life cycle inventory and life cycle impact assessment results, and drawing conclusions and recommendations in conjunction with the goal and scope defined for the LCA study. In order to integrate LCA into building design practice, professionals must interpret these LCA methods in

Interpretation

Inventory analysis

Impact assessment

Figure 1. Steps in LCA method framework (ISO 14040:2006).

conjunction with standards that streamline its application and ensure comparability across studies. Life Cycle Assessments in Building Design Process Whole building LCAs typically focus on environmental quality issues, providing insight through life cycle inventory and life cycle impact assessment results across the building life cycle (Figure 2). The use of LCA in design is similar to the use of costing in that it also provides a summary of

carried out, including functional units, system boundaries, data sources and impact category selection. 2. Inventory Analysis – Determining the resource and energy use, and substances emitted to air, water, and land from processes within the system boundary. This produces life cycle inventory results. 3. Impact Assessment – Characterizing life cycle inventory results to evaluate the significance of their potential

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