Net Zero Homes: Managing Condensation, Air Quality and Risk

Welcome to "Net Zero Homes: Managing Condensation, Air Quality and Risk". Presented by Jeremy Spencer, a longtime sustainable builder and thermal performance assessor, this course addresses the critical side effects of building tighter, more energy-efficient structures. While the industry pushes for 7-star ratings and Net Zero outcomes, increasing insulation and airtightness introduces new complexities regarding moisture and health that every builder and designer must understand.

This course moves beyond the thermal shell design to explore the building science behind happy, healthy homes. You will learn how to identify and mitigate the potential risks associated with high-performance construction, specifically focusing on condensation, mold growth, and indoor air quality. Through a blend of technical theory and practical application, this module equips you with the strategies necessary to protect the structural integrity of your builds and the health of your clients.

Course learning outcomes include:

• Controlling Condensation: deep dive into building science concepts such as relative humidity, dew point, and vapor drive. You will learn four specific control strategies: minimizing cold internal surfaces, reducing water vapor generation, limiting vapor entry into cavities, and designing effective drainage and ventilation pathways.
• Membranes and Climate Zones: Understand the difference between vapor barriers and permeable membranes (Classes 1-4) and how to select the correct products for cool, mixed, and tropical climates to prevent moisture buildup.
• Healthy Indoor Air Quality: Explore the risks of building "too tight" without adequate ventilation. Learn how to minimize off-gassing materials (VOCs and formaldehyde) and implement mechanical ventilation solutions, such as Heat Recovery Ventilation (HRV) and Energy Recovery Ventilation (ERV) systems.
• Managing Client Expectations: Learn how to bridge the gap between the theoretical performance of a NatHERS rating and real-world energy use. This section covers the software assumptions regarding occupancy, appliance usage, and weather, helping you communicate effectively with clients to ensure their satisfaction.

By the end of this module, you will have the knowledge to construct airtight, energy-efficient homes that effectively manage moisture and provide a safe, healthy living environment.