Super-insulated construction, simple yet efficient building systems, and modern solar generation have made net zero energy a realistic project goal for new construction even in cold climates. However, achieving this without the use of red-list materials is a serious balancing act. Moisture control, air tightness, and thermal isolation are critical; evolving envelope products must be tested. This presentation illustrates the modeling and research one team used to target the Living Building Challenge. It will analyze the preliminary building energy data and moisture content of a double-stud cellulose wall employing a vapor open fluid-applied water resistive barrier.