Build Science™ 401 Episode 8 walks through above-grade wall and floor-to-floor transitions, emphasizing how structural framing, drainage, air, vapor, and thermal layers must remain continuous to create a durable, resilient building envelope. Using a real New England home as a case study, Matt Risinger and Steve Baczek explain why engineered floor systems, rain screens, ZIP System sheathing, and simple, repeatable details reduce risk and improve performance. They show how airtight construction, vapor-open assemblies, and balanced ventilation manage moisture more effectively than relying on interior vapor barriers alone. This episode reinforces that good building science prioritizes simplicity, drying potential, and exterior insulation sized appropriately for climate and airtightness. Ultimately, Matt and Steve underscore that integrated systems—not isolated products—are what deliver long-lasting, comfortable, and energy-efficient homes.