In this test I plonked 4 Sherms behind a house, then logged which ones the panzer could see.
He could only see this one.
(and note in the inset that it could see him back)
Below -Confirmation that the panzers LOS to the other 3 Shers was blocked, and they couldn't see him back either.
(Conclusion - houses aren't always guaranteed to block LOS, but at least if he can shoot at you through a house, you can shoot back at him)
More stunning pics on the subject here -
https://www.theblitz.club/message_boards...?tid=39835