I received a dwg file from an architect that I'm having trouble with.

To illustrate the issue - I have a 16'3 line drawn and dimensioned. When I try to draw another line beside it that matches it's size, the line is in fact 412'9 long. Screen shot attached for clarity.

The drawing is apparently at a 1/4" scale but I didn't realize you could draw at a scale in model space? I thought everything was 1:1 until you plot...