It may sound confusing, but here's a brief illustration
the window I'll be installing has the flange around it ready to be nailed in, which I will probably do first instead of putting any caulking just in case.
The reason behind this is for soundproofing, which is why there's the optimal 2-3 inches of air space. If anyone knows anything about soundproofing windows feel free to chime in.
Will this work? (install correctly, soundproof, etc.)