This may not be the thinnest house in the world but this certainly is the narrowest house facade in the world. While I’ve seen some pretty small / thin houses on my walks along the canal, this one seems to be the narrowest. I didn’t find it on my own. I joined a free walking tour guided by a friend and he pointed this out as one of the world’s narrowest houses. Obviously, you can’t disagree by the looks of it.
This should not be confused as the “narrowest in the world” because that title is already claimed by the Keret House in Poland. However, this particular house in Amsterdam has the world’s narrowest house facade. It is much bigger inside.