I am trying to get the correct size for a basement window to be
ordered from Home Depot. The existing aluminum (skinning frame)
window appears to be installed wedged between two steel tube frames.
the outer frame is approx 1 1/2 by 1 1/2 and the inner one 2 by 2. I
am not sure if the two are connected. Without destroying the existing
window how can I get the right size for a retrofit window ?
Is the retrofit window installed from outside to but with the 2 by 2
frame ??

Thanks.