Green design codes and standards now have LCA paths – finally, a performance basis is coming to sustainable design.
Life cycle assessment (LCA) is the latest addition to the life cycle toolbox for buildings. LCA looks at the upstream and downstream burdens throughout the entire building life cycle with a focus on embodied environmental impacts. Embodied impacts become more critical as operating consumption, such as energy and water, is reduced through optimization of design and building management.
LCA provides a quantitative basis for environmentally improved designs, removing the guesswork, unintentional greenwashing and burden shifting (when improvement in one life phase merely creates more burden in another phase).
The Athena Sustainable Materials Institute is the first North American organization dedicated to the use of LCA in construction. The Athena Institute is well-known for its common-good mandate to develop LCA data on construction materials and systems and to make these data accessible to building designers through user-friendly tools such as the Athena Impact Estimator for Buildings.
LCA and LEED®
The LEED rating system has previously experimented with LCA in a now-retired pilot credit. Currently, two new MR LCA-based credits are in LEED v.4.
The new “building life cycle impact reduction” credit, option 4, gives three points if LCA is used during design and results in a reduction in environmental impacts for a final design compared to a reference building. The Impact Estimator is ideal for this task and will be the tool of choice for design professionals that wish to earn this credit. There are alternate software packages that can also serve this purpose, however these are complex and time-consuming tools suitable only for LCA professionals.
Another new credit, “building product disclosure and optimization – environmental product declarations”, is earned by including enough products with LCA-based information: either an LCA report or an environmental product declaration (EPD). Designers will need to seek this paperwork from product suppliers, who will develop it after completing LCA studies for their products. This is one reason the Athena Institute’s manufacturing clients contract us for LCA studies.
LCA and Green Globes™
Green Globes was the first national building rating system in North America to integrate LCA as a credit. The Athena EcoCalculator for Commercial Assemblies was the original basis for this credit; in fact, the EcoCalculator was developed to serve this purpose. In 2010, ANSI/GBI 01-2010: Green Building Protocol for Commercial Buildings was officially approved; it is derived from Green Globes. In this standard, LCA is included as an alternative compliance path to prescriptive material requirements. Green Globes has since been updated, and the LCA credit has been significantly revised. It is now a whole-building comparative LCA credit, where the final design needs to show improvement over a reference design. The Athena Impact Estimator for Buildings is the best choice to earn this credit.
LCA and ICC 700
The International Code Council (ICC) 700 National Green Building Standard is a residential green standard initiated by the National Association of Home Builders. The current (2012) version gives points for reducing environmental footprint on the basis of life cycle assessment. Both the Athena Impact Estimator and the Athena EcoCalculator are well-suited for this credit.
LCA and the IGCC
The (current) 2012 International Green Construction Code from the International Code Council, section 303, offers whole-building LCA as an alternative compliance path to the prescriptive material requirements in section 505. Final design must show improvement over a reference building. The Athena Impact Estimator is the right tool for compliance with this section.
LCA and ASHRAE 189.1
The (current) ANSI/ASHRAE/USGBC/IES Standard 189.1-2011, whole-building LCA is available as an alternative performance compliance path to prescriptive material requirements. Final design must show improvement over a reference building. The Athena Impact Estimator is the right tool for compliance with this section.
The 2010 California Green Building Standards Code (current version with 2012 updates) offers LCA at either the whole-building level or for building assemblies, under non-residential voluntary measures. A whole-building LCA can be used to bypass prescriptive material requirements. Both the Athena Impact Estimator and the Athena EcoCalculator are well-suited for compliance.