Blower door testing is often done to help remedy a leaky home. Or near the end of the building process of a new construction home, when the paint is done, final doors and windows are in place, and the weather stripping is installed. This is a great time to find out your possible leaks in a home are. Doing leakage testing at different stages of construction can help diagnose issues and fix them while the primary air barrier is still accessible. The caveat to this early testing is that you must seal up any window or door opening that might not be filled yet, otherwise you won't be able to pressurize the building enough to look for the leaks.