In Edit Mode, X and Y units are consistent, Z is wrong

[Matney X]

I'm trying to make a model of a real space, and Blender's measuring has got me going crazy. If I build a doorway that looks like a square (which isn't what the space looks like, but it's the best example I can think of), the distance across the top is 3' (using imperial units), and the height is 262' 2.9"! Is there something I'm absolutely missing?

[brasshat]

Without a screenshot of the whole viewport, of a link to a blend file, I'm less confident in my answer than I might be otherwise. Having written that, the first thing I'd look at is your workflow. One thing that would result in something like what you show is if you scaled the object (in object mode), but did not apply the scale (CTRL-Akey).

ns