Please Help!!! I
need the advice of the Pros here more than ever. Just had my 3rd
contractor out to quote on my replacement window project. I am replacing my
33yr old aluminum clad windows in a modified log cabin in CT. The existing windows are all Peachtree
casements, 5 singles, 8 twins, and 1 triple. I was seriously hoping to be able
to get away with insert casement replacements as I do not want to disturb the
custom trim work on the interior or exterior if at all possible. Everything was
going fine until today when this contractor said that I wouldn’t be able to use
inserts in the factory mulled frames. His explanation was that the mulled units
were created by screwing two or more single units together. If he cut the
mullions out it would ruin the structural integrity of the top and bottom
frames. To make matters worse he said that because of the unusual log construct
he didn’t even want to venture a guess at what the job would cost and that he
didn’t think many other contractors would either.

After I had time to think I wondered why the previous 2 contractors gave me reasonable bids on
casement replacement inserts in the same configuration and said nothing about
this. When I ventured outside to examine the windows I could clearly see that
the aluminum cladding (extrusion I believe) on the top and bottom window frames
were one piece and that the mullion just seemed to be bonded in place (pictures above).

So, my question for the Pros here is what do you think?
I am including this
pdf which has an exploded view of my existing windows. Unfortunately it's
not one of a mulled unit. Please help :)!!! https://www.pwdservice.net/sites/default/files/arielcas.pdf