Hi,
Thank you for reporting the issue here and I am very sorry about the experience!
First, about the expression's unit conversion, I would like to make sure that the "decimal inches" is set for "Length Unit" in Options > Project Preferences >
Calculation Units & Rules. This will ensure the correct expression unit in schedules.
However, I couldn't find the reason why it was converted to 0'-6 1/1". I'm not sure if this is the case that has been reported here:
https://archicad-talk.graphisoft.com/viewtopic.php?f=34&t=66426
I look forward to hearing from you about this issue. Thank you very much!
Best regards,
Minh
Minh Nguyen
Technical Support Engineer
GRAPHISOFT