If the old door entry system is obsolete and it is necessary to
change it for a new one, the homeowners must address the problem without
there being any opposition, given that is forms part of the maintenance
of the property.
Then, whether a door entry system or video door is chosen is a question that must be discussed in the homeowners meeting taking into account that the outdoor panel and the wiring are common costs, whereas the telephone or monitor of each apartment is chosen and paid for by each homeowner.
Each neighbor may choose whether they prefer a telephone or monitor, according to their needs. The only decision for which there must be agreement is whether to install a panel with a camera and check the wiring. Other than that, the choice of each apartment is theirs alone. Anybody could even opt for a telephone now and later on, if they change their opinion, change to video.