The only thing I could suggest is that you express your concerns to the local council. Unfortunately there are no hard and fast rules on how many people can be accommodated in one building, and there is little if any consistency between our local government bodies in how well they address overcrowding issues. With less affordability of housing in our major cities (despite political denials!) unfortunately this situation of cramming more people into buildings is more prevalent, affecting single dwellings as in your case and multiple occupancy apartments.
DaveB