Episode 11 of Build Science™ 401 covers an in-depth discussion on system integration in high-performance building envelopes, specifically on how the four control layers integrate into a vented roof assembly. Matt Risinger and Steve Baczek explain how various layers—ZIP-R9 sheathing, SIGA Majvest building paper, and SIGA Majrex smart vapor retarder—are connected to create continuous air and vapor barriers, while vented roof assemblies and baffles ensure proper airflow and drying potential. They discuss venting strategies for shingles and rain screen assemblies, including the importance of leaving vent spaces uncaulked to prevent pressure issues. Also, Matt and Steve discuss insulation strategies, including air-permeable blown-in insulation up to R80, and emphasize the importance of vent spacing, moisture management, and climate-specific considerations. The episode concludes with a highlight on builder-friendly techniques, product choices, and the role of redundancy to prevent failures.