Roost-Arch

Mulling two units together seems the way to go. I found I can set the top unit bottom frame width and bottom unit top frame width to 0" and eliminate the frame piece. A little tweaking of sash offsets for the top can get you really close. Thanks for the help.

If mulling them together is there any way to get rid of the frame piece between units?

I'm getting started on modeling an old mansion for some renovations and haven't done much with custom windows in Chief. Wondering if anyone has any tips on how to accurately model these arch top triple-hung windows. I could get something close by using a triple awning but I'm curious if anyone has ideas for getting the sash offsets so it appears more correct in renderings.