The built environment is both a major contributor to climate change and one of the most powerful areas where meaningful change can happen. This presentation introduces the key ideas, terminology, and design strategies that can help professionals better understand and reduce the carbon impact of buildings. The presentation begins with the current realities of climate change and the risks ahead, followed by key carbon terminology that creates a shared foundation for the discussion. It then explores Passive House as an efficiency-first approach and examines how net-zero housing balances energy demand with on-site renewable energy production. The low-carbon design section introduces bio-based materials, engineered lower-carbon alternatives, material transparency, and practical ways to reduce both operational and embodied carbon. The presentation concludes with a carbon-conscious decision-making strategy that helps professionals move from awareness to action by considering building size, energy performance, electrification, material selection, durability, sourcing, and the full life cycle of a project.