[kach22i]

I looked in my dated barn book and could not find the image I had in mind.

The barn book is a pretty picture large format book, good for ideas. I'm not claiming you need to seek it out on Amazon used books and acquire it. There may be better books out there for your stated goals. It is a nice coffee table book though.

BARN
1992
Houghton Mifflin Company
ISBN 0-395-57372-6

Be aware that in most states there is a code book just for renovation. It more or less says; any new work must meet the new code, old stuff can be left alone if not increasing structural loads by more than X% or increasing occupancy loads beyond a certain point.

Keep in mind that mixing commercial and residential uses; either side by side or above and below each other makes for a complex project (fire walls and the like).