<p>Structural engineers make design decisions based on objective criteria. From the strength of materials to finite element analysis, engineers rely on quantifi able metrics to design structural systems. With the emergence of sustainability objectives within the design profession, engineers have a unique opportunity to utilize their analytical expertise to produce structural systems with a positive impact on the natural environment. This chapter presents sustainability goals, an overview of life-cycle assessment (LCA), life-cycle assessment case studies answering common engineering questions, green design rating systems, and emerging trends in measuring environmental performance.</p>