During a blower door test, we’re measuring how much air leaks into and out of the building through the thermal envelope. Windows are a major part of that envelope, and if they’re not properly sealed, air can easily move around the framing and into wall cavities.

If air is escaping around the range hood duct, your thermal envelope may not meet the required air leakage limits. That means you fail the test and have to go back and fix the issue—usually with extra labor, delays, and a return trip for the inspector.

Any penetration in the building envelope—whether for plumbing, electrical, or HVAC—must be properly sealed to prevent air from moving in and out of the structure.

During a recent inspection, we identified air leakage through a door frame—an often-overlooked issue that can compromise your building's thermal envelope. This typically occurs when top and bottom wall plates behind the drywall aren't properly sealed, allowing air to escape through trim gaps. Such leaks can lead to energy inefficiency and potential inspection failures.