Sustainable Building Technical Manual - Etn-presco.net

SECTION CMaterials andS p e c i f i c a t i o n sLife-Cycle Assessment and its Application toGreen Building PrinciplesImproving the environmental performance of a building requires a systematic and comprehensiveunderstanding of all the environmental impacts that occur throughout thebuilding’s life cycle. This approach—which may also be applied to products and activities—hascome to be known as life-cycle assessment (LCA). When applied to a building,the life-cycle approach seeks to examine and analyze all environmental effects of thatbuilding, from the acquisition of all the materials, energies, and natural resources thatultimately go into the building to the point in time when the building has completed itsuseful life and is demolished. In addition, the life-cycle approach seeks to balance environmentalconcerns with traditional issues that have always affected decisions and choicesin the building industry: function, performance, aesthetics, and cost. Equipped withthe knowledge and understanding provided by the life-cycle approach, design professionalsare able to make the decisions and choices that can lead to genuine improvement in abuilding’s environmental performance.AuthorDr. James A. TshudyLife-cycle assessment provides the most thorough assessment approach to understandingthe environmental impacts of buildings and building materials. Although frequently citedand discussed, LCA is not thoroughly understood or utilized by many in the buildingindustry. As a result, the application of some well-intended green building principles canbe misguided. Often, materials or products are compared and decisions made on the basisof one or a few isolated environmental attributes without consideration of the full arrayof environmental impacts and implications present in the total life cycle. Such simplisticdecisions can be risky and lead to a poor choice. For example, if “product A” is manufacturedfrom a certain recycled material and “product B” incorporates no recycled material,the assumption usually is that A is a better choice than B. Or if A is made of natural materialsand B is not, A is usually assumed to be the preferred environmental choice. Soundscience and LCA may reject such a choice; making the proper decision requires a morethorough analysis.