Practicing ArchitecturePracticing Architecture
The AIA Guide to Building Life Cycle Assessment in Practice details the tools and tactics of balancing the costs and benefits of material and systems selection based on resource consumption and pollution from fabrication, shipping, construction, operations, and end-of-life deconstruction.
By comparing the whole building and individual components, in a process established by ISO 14040, architects and engineers can calculate environmental impacts at the outset of a project, and refine those calculations as the project proceeds, to show owners what the potential is for a proposed design option to cause or mitigate global warming, acidification, eutrophication (excess nutrient leaching that causes, for example, algae bloom), fossil-fuel depletion, smog formation, ozone depletion, ecological toxicity, and water use.
The life-cycle assessment (LCA) process includes all participants in the planning, design, construction, and operations of a facility and begins with setting the goal and scope of the LCA. The LCA might focus on one specific impact, such as global warming potential. Step two, inventory analysis, would then quantify the input and output of each element of the design being analyzed to determine how many units of greenhouse gases will be released or embodied (in this case, measured as CO2 equivalents). The impact is analyzed, based on the set goals, and decisions can be made based on the resulting interpretation.
The process is heavily dependent on the regional accuracy of databases and hampered by the one-off nature of building design and construction, the guide notes. Government and nongovernment organizations are currently working to refining both the databases and the software that crunches the numbers to make sense of the reams of raw data for non-technical decision makers.
The guide uses case studies to explain the process and the many computer-aided assessment tools and databases of product performance and regional conditions that exist now or are in development.
“As the architectural and construction industries increasingly emphasize sustainability, more comprehensive methods are being developed to evaluate and reduce environmental impacts by buildings,” notes the editorial team that developed this guide, members of the AIA Committee on the Environment. “Life Cycle Assessment (LCA) is emerging as one of the most functional assessment tools; however, presently there is a scarcity of clear guiding principles specifically directed towards the architectural profession in the use of building LCA during the design process. In this paper, we are providing those guidelines to help architects understand and use LCA methodology as part of the design process by identifying scenarios for the use of LCA in the design process and providing a set of proposed guidelines for the conductance of whole-building LCA.”
Written by architects for architects, AIA Guide to Building Life Cycle Assessment in Practice is an essential introduction to this rapidly developing field of cradle to grave building resource management. It recognizes the current limitations of LCA—particularly the current nascence of client demand and comprehensive databases—and looks ahead to the next emerging discipline in measuring building design, construction, and operations sustainability.