Both the interior door and the balcony connecting door have to be unlocked by housekeeping however the interior connecting door also has a deadbolt to use if you don't want that door open at some point. The room balcony doors have a curtain so if you're concerned about family members from the connecting balcony room peering in at night, the curtain will block that while still allowing daytime access. In our case, we simply have the connecting doors unlocked at the beginning of the cruise and then knock on the interior doors if it's closed. (each room has a separate door on the ships I've been on).