Here's something I didn't know until I watched a pro do it: apparently, if you skip sealing the window frame properly (like with that expanding foam or tape stuff), you can lose way more heat in winter than through the glass itself. Wild, right? I always figured the glass was the weak spot, but nope—it's those little gaps around the edge. Anyone else surprised by this, or have tricks for getting a good seal without making a mess?
Funny, I thought the same thing for years—just assumed the glass was the culprit. Turns out those tiny gaps are basically a highway for drafts. I tried that foam once and made a total mess, so now I use the low-expansion stuff and painter’s tape to keep it tidy. It’s not perfect, but way better than freezing by the window every January. Honestly, sealing made more difference than swapping out for double-pane glass did in my old place.