Vermont energy code changes raise concerns about mold and building safety

A critical discussion on building codes and energy efficiency took center stage during the Vermont House Energy and Digital Infrastructure meeting on April 29, 2025. Experts voiced concerns about the implications of the new Vermont Energy Code, which mandates a layer of exterior insulation on homes, potentially compromising the ability of walls to dry out effectively.

The meeting highlighted a fundamental principle in construction: water is the enemy. Builders and experts emphasized that while keeping water out is essential, managing condensation is equally crucial. Condensation occurs continuously in winter, and if not properly addressed, it can lead to significant structural damage. One expert noted that older farmhouses often survive due to their lack of insulation, which allows for better moisture management compared to modern insulated homes.

The new energy code, effective February 2024, has raised alarms among builders. They argue that while the code aims to reduce energy transmission through walls, it inadvertently hampers the drying process, leading to potential rot and mold issues. A vivid example was shared of a ten-year-old house suffering severe damage due to improper wall assembly, resulting in costly repairs that were not covered by insurance.

Participants in the meeting also discussed the broader implications of Vermont being one of the few states without a comprehensive building code. The absence of enforced standards leaves builders liable for construction choices, often without a clear benchmark for quality. This situation raises concerns about the long-term safety and durability of homes in Vermont, especially as the state faces a housing crisis.

The conversation underscored the need for a balanced approach to building codes—one that prioritizes safety while also considering energy efficiency. Experts called for a collaborative effort to refine the energy code, ensuring it serves both builders and homeowners effectively. As Vermont navigates these challenges, the focus remains on creating safe, sustainable housing for all residents.