Trickle Vent Legal Requirement: Why Airtight Homes Need Background Ventilation
The real reason trickle vents became mandatory Questions about trickle vent law usually get framed as a legal nuisance, but the rule exists because modern windows changed how homes breathe. Older timber frames leaked air through joints, gaps, and tired seals. A new sealed unit can cut that leakage dramatically. Once that accidental airflow disappears, moisture and stale air have to leave and enter somewhere else. Trickle vents are the controlled answer. ...