5 Things You Need to Know about Life Cycle Assessments

ellie_colorEllie Troxell
Sustainability Associate, Civil Engineering

There has been discussion for a number of decades about the environmental impacts of materials and processes, but only recently has a tool been developed in an intentional way to measure those impacts.  The newest addition to the life cycle toolbox is the Life Cycle Assessment (LCA).  LCA’s provide valuable information for exploring decisions related to the environmental impacts of buildings, materials, products, and services.

  1. A Life Cycle Assessment is an evaluation of the environmental impacts of products, processes or services through their life cycle.

The International Standard for Organization (ISO), a world-wide federation of standards bodies, has standardized the LCA framework.  ISO-compliant LCA is the most reliable and referenced technique used to verify environmental impacts.  According to ISO 14040 and 14044 standards:

Life cycle is defined as the “consecutive and interlinked stages of a product or service system, from extraction of natural resources to the final disposal.”

lifeLife Cycle Assessment (LCA) is defined as a “systemic set of procedures for compiling and examining the inputs and outputs of materials and energy and the associated environmental impacts directly attributable to the functioning of a product or service system throughout its life cycle.”

In simpler terms, LCA is a systemic evaluation of the environmental impacts of products, processes or services through their life cycle, and—most importantly—provides a tool that supports making sound, considerate environmentally-relevant decisions. It is also worth noting at this juncture that LCA’s do not analyze economic or social impacts—they focus exclusively on the environmental considerations for a product or service.

  1. Life Cycle Assessments are driven by environmental accountability, corporate sustainability, and procurement policies.

In short, pretty much everyone that makes anything has a reason to use LCAs.  LCAs have been conducted on a variety of products and services across a number of sectors—from jeans to jet engines, trash disposal, and computers.  Various factors are driving this new trend.  First, regulations are moving towards “life cycle accountability”, the idea that the manufacturer is not only responsible for the direct production impacts of a product or service, but its inputs, use, transport, and disposal.  For example, the LEED rating system currently has two MR LCA-based credits in LEED v4, following a now-retired LCA pilot credit.  Green Globes, the International Code Council (ICC), the International Green Construction Code (IGCC), ASHRAE, and Calgreen now all provide alternative LCA compliance paths.  Second, business is voluntarily participating in initiatives that involve LCA and other elements of stewardship.  Third, consumer markets and government procurement parameters have started to cite environmental precedence.

  1. Life Cycle Assessments follow a 4-phase process.

So now you know what an LCA is, and why they are useful.  But how might you go about actually doing a Life Cycle Assessment?  The following four main phases briefly define the LCA process:

Goals & Scoping – Identifies the purpose of the LCA, determines which environmental concerns will be included in the study, and notes all assumptions based on the goal definition.

Inventory – Quantifies the life-cycle for all environmental inputs and outputs of the parts of the building, material, service, or product system involved in the LCA.

Impact Assessment – The assessment takes inventory data given the inputs and converts the information to indicators for a given category. Typically, LCA reports on these environmental effects due to a product, building or service:

  • Fossil fuel depletion
  • Other non-renewable resource use
  • Water use
  • Global warming potential
  • Stratospheric ozone depletion
  • Ground level ozone (smog) creation
  • Eutrophication of water bodies
  • Acidification and acid deposition (dry and wet)
  • Toxic releases to air, water and land

Interpretation – This last step is an analysis of the data evaluating opportunities to reduce waste at each step of the product life-cycle and defines whether the conditions of the goal and scope have been met.

For a typical product, the environmental life cycle impacts (commonly known as “cradle-to-grave” impacts) include the extraction of raw materials, the processing, manufacturing, and fabrication; the transportation or distribution of the product to the consumer; and the disposal or recovery of the product after its useful life.  It is worth keeping in mind, however, that these may not be applicable to every product; there may be instances where one or more are not of particular environmental concern.

  1. There are a wealth of tools to make Life Cycle Assessments easier and faster to conduct.

There are a few tools already available for anyone interested in conducting an LCA.  The following tools differ due to the purpose of the LCA.  Explore which might be the best fit for your purpose:

  1. The two-sides to Life Cycle Assessments: Benefits & Pitfalls.

While LCAs highlight important considerations in the development of a product, they are not yet a silver bullet for environmental concerns.  Thus, it is worth keeping in mind both the benefits of LCAs, as well as those areas where they may fall short.

Benefits Pitfalls
• Pragmatic standard for green design (performance-based)

• Ability to evaluate opportunities to affect environmental improvements

• Introduces the notion of calculating the environmental footprint of a product/service/building

• Greater awareness of environmental implications

• Creates common metrics that can be shared and compared to help choosing one path over another

• Improve product/ corporate image

• Reduce environmental impact & waste

• Difficulty in assessing the environmental effects of resource extraction (biodiversity, water quality, soil stability not easily measured and only minimally addressed in LCA)

• Can be costly and time-consuming limiting their use as analysis techniques

• Quantity of assumptions (all rough estimates)

• Limited ability to account for land-use impacts



Athena Institute (2016). About LCA. Retrieved from http://www.athenasmi.org/resources/about-lca/who-does-lca-why/

Williams, Aida S. (2009). Life Cycle Analysis: A Step by Step Approach. ISTC Reports. http://www.istc.illinois.edu/info/library_docs/tr/tr40.pdf


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