Earlier quoted context omitted.
The only row house's I know of share side walls. Because they're all built in a row.
If you look closely when walking around a neighborhood of row houses you'll find that they don't actually share side walls. Each row house has its own exterior walls with siding / exterior finish that may end up directly adjacent to the next house's exterior wall. This is apparent in areas where one row house has been torn down or is larger than its neighbor. Of course sound and fire might travel through these more e…
The row houses I'm thinking about are in Philadelphia, and I think most other east coast cities. Occasionally you'll see one with the neighboring house(es) demolished, and there are usually remaining bricks from the missing house on the now exterior wall.