The intent of this Design Guide is to introduce the topic of sustainability, present its elements, and explain how it affects the design of lighting in process and product. This document is structured into two major sections. Section 1.0 introduces sustainable design and lighting impacts. Section 2.0 is an overview of sustainable lighting design and describes nine elements that address the central issues facing the lighting practitioner today. The next three sections (annexes) are organized into areas that address assessment and life cycle stages of lighting.