You know that building energy efficiency is critical to meeting our society's carbon reduction goals, and you see it driving public policy, codes, and new certification programs. But where do you start to digest it all? It's overwhelming! This session takes a step back and gives an introduction to the underlying building science, the physics, and their connections to comfort, health, and efficiency. Find out why it matters so much. Then the session will give an overview of what's happening now in codes and certification programs and policies - providing guidance on next steps professionally and also on what conference sessions might be most useful to you through the day.