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Life Cycle Assessment


Life Cycle Assessment (LCA) aims to quantify the environmental impacts that arise from material inputs and outputs, such as energy use or air emissions, over a product’s entire life cycle to assist consumers in making decisions that will benefit the environment. LCA is typically a "cradle-to-grave" approach, which begins with the gathering of raw materials from the earth to create the product and ends at the point when all materials are returned to the earth.

The goal of LCA is to:

  • Quantify or otherwise characterize all the inputs and outputs over a product’s life cycle
  • Specify the potential environmental impacts of these material flows
  • Consider alternative approaches that change those impacts for the better
Flowchart showing a life cycle system boundary. The inputs are energy, water, and raw materials. These lead to the system boundary, which includes raw material acquisition; manufacturing, processing, and formulation; distribution and transportation; use, reuse, maintenance; recycle; and waste management. The outputs are useable products, water effluents, airborne emissions, solid wastes, and other environmental releases.
Figure 1: Inputs and outputs over a product’s life cycle

It is important to take into consideration the entire life cycle of materials, systems, and the whole building when making design or purchasing decisions.

Benefits of LCA

Provide comprehensive view of the environmental impacts See more than just the “use” phase
Quantify environmental effects such as overall energy consumption or air emissions Recognize inefficiencies or significant changes across life cycle phases
Allow comparison of alternatives "apples to apples" Reduce overall environmental impact and costs (as in an economic input-output LCAnon government site opens in new window)

Challenges with LCA

Defining LCA boundaries and scope Where do I want to draw the line? What attributes am I interested in comparing against one another? How far down the chain do I want to identify and quantify these material flows, and is that data even available?
Data availability Is data available to quantify material inputs and outputs at all stages of my defined scope? Is this data from a reliable source (e.g., manufacturer)?
Quantifying environmental impacts How can these material flows be quantified into environmental categories (e.g., global warming)?
Weighting impacts across stakeholders What environmental category are we most concerned about (e.g., global warming, energy use, acidification) and how does it compare to other environmental attributes?

Related Topics


Assessments

Assessments are essential tools for linking science and decision making. They survey, integrate, and synthesize science, within and between scientific disciplines and across sectors and regions.

Source: USGCRP: Assess the U.S. Climate - What are assessments?

Carbon Footprint

A Carbon Footprint is the amount of greenhouse gas emissions (in units equivalent to carbon dioxide emissions) emitted by an entity, be it a person, building, company, or country.

Construction

Embodied Energy

A measure of the energy used to harvest, manufacture, process, bring to market, and dispose of a product. In Life Cycle Analysis (LCA) of building materials, embodied energy helps identify the true energy cost of an item. This accounting method attempts to quantify the fossil fuels, nuclear energy, and other forms of energy that are involved over the material's life.

Emissions

Emissions are the discharge of a substance. In the building’s context, emissions usually refer to greenhouse gas emissions into the atmosphere (e.g., the release of carbon dioxide during fuel combustion).

Green Building

High-performance buildings exhibit environmentally responsible intent and perform in a resource efficient manner. They meet the needs of the occupants that live and work in them in a way that minimizes demand for natural resources and reduces or eliminates waste. High-performance buildings save energy, water, materials, protect the indoor environment and are designed to evolve as occupant needs change. Such buildings are generally more comfortable, healthy, durable and adaptable over time.

Greenhouse Gas (GHG) Emissions

A range of human activities cause the release of greenhouse gases into the atmosphere (e.g., the release of carbon dioxide during fuel combustion). These gasses can damage or be trapped in the earth’s atmospheric layers, contributing to global climate change.

EPA | Greenhouse Gas (GHG) Emissionsopens in new window

Life Cycle Assessment

Life Cycle Cost Assessment (LCCA)

Materials and resources all have environmental, social and economic impacts beyond their use in a project. Impacts occur during harvest or extraction of raw materials, manufacturing, packaging, transporting, installing, use, and end-of-life disposal, reuse, or recycling. These “cradle to cradle” impacts should be considered when purchasing materials. The formal study of this process is known as Environmental Life Cycle Assessment (LCA).

Similarly, Life Cycle Cost Assessment examines the costs and savings throughout the life cycle of a building material. For example, energy efficient equipment and appliances can be more expensive when initially purchased but will save energy (and money) throughout the life of the project. Therefore, it may make sense to invest in more efficient equipment that costs more up front but saves money and energy over time.

The Sustainable Facilities Tool allows you to compare life cycle costs for materials, as well as other environmental criteria, by following the green dots and clicking "compare materials" in Explore Sustainable Workspaces.

Also, check out information on LCA at the Whole Building Design Guide:
WBDG | Life Cycle Cost Analysis (LCCA)non government site opens in new window

Life Cycle Thinking

Recycling

Glass, plastic, aluminum, cardboard and paper (including glossy magazines, envelopes with plastic windows and sticky notes) can all be easily recycled.  Depending on the waste hauler, recycling bins can include commingled waste (i.e. all materials are collected in one bin) or they may require separated waste (i.e. one bin for paper, one bin for plastics, etc).  By recycling products, materials are sent back to the marketplace rather than to the landfill. 

EPA | Recycling Basicsopens in new window

Reuse (Waste)

Similar to recycling, reuse refers to finding new uses for items instead of sending them to landfills.  Can furniture be reused in another department of the company? Can electronics be donated to charity? Even using an empty soda bottle to make a hummingbird feeder is a way to reuse items instead of trashing them.

http://consumersunion.org/pdf/ZeroReport.pdfnon government site opens in new window

EPA | WasteWiseopens in new window

Solid Waste

Waste comprises all materials that flow from a building to final disposal.  Examples include paper, grass trimmings, food scraps, and plastics.  Responsible stewardship tries to divert as much waste as possible from the landfill.  This can mean recycling paper, mulching or composting grass trimmings, and reusing large items, such as furniture.

EPA | Land, Waste, and Cleanup Topicsopens in new window

Source Reduction

Source reduction reduces the volume or toxicity of waste generated. Source reduction occurs before materials have been identified as “waste”. For example, building management can designate reuse centers for office supplies and other reusable goods. Another example of source reduction is implementing a paper reduction campaign through double sided and electronic printing.

Sustainability

Sustainability and sustainable mean to create and maintain conditions, under which humans and nature can exist inproductive harmony, that permit fulfilling the social, economic,and other requirements of present and future generations.

Sustainable Purchasing

Purchasing managers should create purchasing plans and programs that give preference to items containing recycled content, certified wood, and rapidly renewable materials, as well as items that are energy efficient, non-toxic, durable and locally manufactured, harvested and / or extracted.  Further, purchasing managers should prioritize vendors who promote source reduction through reusable or minimal packaging of products.

EPA | Greener Productsopens in new window

Department of Energy | Guiding Principlesopens in new window

Virgin Materials

Virgin materials are natural resources that are extracted in their raw form that are traditionally used in industrial or manufacturing processes.  Examples of virgin materials are timber, plastic resin derived from petroleum refining process, and mined/processed metals.

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Did You Know?

Energy savings performance contracts (ESPCs) allow federal agencies to implement cost-saving facility energy improvements with no up-front capital costs. Source: U.S. DOE Federal Energy Management Program (FEMP), Energy Savings Performance Contracts for Federal Agenciesopens in new window


Case Study

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