One other thing you should know: Homespun stretches quite a lot in the vertical dimension. If you're doing somethink long such as the sweater coat you mentioned, you should probably measure the length from hem to armhole shaping vertically (if that's making any sense).
I did a long cardigan sweater fro my DD a couple of years ago, measured everything flat, and when it was all sewed together, and she put it on, the length was about 8 inches too long and the sleeve length hung over her hands with the armholes about half way to her waist.
I ended up giving this to DSOs DD - my DD is 5'2" and very petite and Megan is 5'11" and quite statuesque. It fit her quite well, fortunately! I'm now redoing DD's (when I feel like working on this, which is seldom since I've grown to detest this project) having changed my needle size downward by about 4 sizes to get a stiffer fabric and adjusting ALL!!!!! the measurements to take the stretching into account!! Tlak about rewriting the pattern!
THIS is what made me HATE working with Homespun!! Beautiful colors, BUT........
Suggestion for measuring "vertically". Lleave the piece on the needles or if too wide slide onto long circular needle, hang it from a coathanger up against a wall somewhere, let it "relax" for awhile and measure that way.
The weight of a long piece of knitting tends to make the stretch even worse.
I hope you have an easier time than I did. Good Luck!!!!!