Materials and resources all have environmental, social, and economic impacts beyond just their “use” phase in a project. For a material, impacts occur during harvest or extraction of raw materials, manufacturing, packaging, transporting, installing, using and ultimately discarding (through reusing or recycling). Similarly, financial costs arise during the initial purchase, with installation, operation and maintenance, training, removal and disposal. Considering these environmental impacts and financial costs over the entire life span of the product or material is what is known as a life cycle perspective, or life cycle thinking.
A life cycle perspective provides the relevant information needed to make good decisions — to protect the environment, improve the lives of people who produce the goods, and safeguard the health of people who use them.
Two common ways to apply a life cycle perspective to buildings include Life Cycle Assessment and Life Cycle Costing. This clearinghouse focuses on the environmental impact of products and buildings, so after comparing and contrasting the two concepts below, the remainder of this section will address LCA.
Comparing life cycle assessment and life cycle costing
Life cycle assessment
LCA is a systematic study examining the environmental impacts of a product from raw material extraction through production, use, and final disposal. Assessments can be “cradle-to-grave”, “cradle-to-gate” (before distribution), or “cradle-to-cradle” (cyclical or regenerative process).
Life cycle costing
LCC is an economic analysis that considers both initial investment costs and future costs over a specific time period. The goal is to compare the overall costs of project alternatives and to select the design that ensures the facility will have the lowest total cost of ownership.
Comparison
Here is a simple comparison to clarify the distinction between LCA and LCC:
| Aspects | Life cycle assessment | Life cycle costing |
|---|
| Main focus | Find options that reduce environmental and human health impacts | Find options with lowest total ownership cost |
|---|
| Scope | Typically, all life cycle stages | Typically, Construction to End of Life |
|---|
| Elements | Impacts on human health, ecosystem quality, and resource use | Costs |
|---|
| Metrics | Each area of protection has its own metric | Money only |
|---|
| Standards and methodology | ISO 14040 and 14044
High level, with room for interpretation | NIST Handbook 135*
GAO Cost Estimating and Assessment Guide (2020)
Prescriptive, formulaic |
|---|
*As applied to the design of energy conservation measures for federal building projects, the LCC process is mandated by law and defined in the Code of Federal Regulations, Title 10, Part 436, Subpart A: Methodology and Procedures for Life Cycle Cost Analyses. Learn more about building life cycle cost programs.
U.S. General Services Administration
