Steve Baczek discusses the critical concept of airtight construction by focusing on air barriers and the importance of maintaining a continuous “red line” around the structure. Using a construction site example, he explains the distinction between inside and outside conditioned spaces and how to preserve that boundary through proper insulation and sheathing. He emphasizes building a sealed “box” first and attaching elements like porches afterward, without disrupting the integrity of the enclosure. This approach improves air tightness, thermal performance, moisture control, and overall durability. Baczek passionately advocates for consistent building practices and offers educational resources through his podcast and online content.