I have three of these metal-framed basement windows which I would like to replace but I am unsure of what dimension I should measure and use for the replacements.
Initially I measured the outside dimension (32 1/2" x 16 1/4") but on closer inspection, it looks like the metal is just folded up against the concrete. This leads me to think I should use the inside dimension (30 1/2" x 14").
What is the correct way to measure for replacement windows in this case?
EDIT: Included some outside pictures