all the questions pertain the second floor level
My house is
semi-detached 2 story 1920 house (each side is approx 18 feet wide ) .
vertical stud(2×4 @16) is balloon framing ( from basement to attic its one continuous piece ) and brick are placed in the cavity { this is called brick...
https://photos.app.goo.gl/8y6rmxnJm4uooxdt6
question 1 is my stud(at location of (the party brick wall/stud /infill brick) continuous from foundation to roof?
Question 2 why don’t I see my neighbors floor joist ?
Question 3 does my neighbor have its own 4 inch wall to support their floor...