This chapter explored new ways to build green by using sustainable waste materials. It focuses on the circular economy, showing how waste like recycled concrete, glass, and plastic can find new life in construction. This cuts down on environmental harm and uses fewer resources. Key methods include life cycle assessment (LCA) to evaluate environmental perks, green design principles to make the most of materials, and cutting-edge recycling technology to turn waste into top-notch building materials. Real-world examples show successful uses and the resulting economic and environmental gains. The chapter also tackles hurdles like rules that get in the way, market acceptance, and tech limits, offering ways to get past these roadblocks. By bringing sustainable waste materials into building practices, the industry can take big steps toward sustainability. This boosts new ideas and creates a tougher built environment.