On this week’s episode of All About Home Construction, we’re breaking down the blower door test — what it measures, what the grades mean, and how to understand those “theoretical hole” sizes. We’ll explain how air leakage impacts your home’s comfort, efficiency, and energy bills, and share practical steps you can take to tighten up an existing home. From sealing attic penetrations and basement rim joists to weatherstripping doors and improving ductwork, we’ll cover the best ways to reduce air leakage. Plus, we’ll talk about how making your home tighter might also mean adding proper ventilation with an HRV or ERV. If you’ve ever wondered how leaky your house really is — and what you can do about it — this episode is for you.