OCs might like to consider a rule/bylaw/article like the one we recently adopted. Essentially we now have in place a rule that states that anything installed on common property that is solely for the benefit of one unit (aka ‘lot’) is the responsibility of that unit owner to repair and maintain regardless of whether permission to install it was granted or not, and the unit owner must ensure that it remains in a safe condition and is not to the detriment of the appearance of the common property. Also, the OC can take action to make such things safe or remove them if the owner does not comply (with reasonable notice etc) and bill the owner.
The above example would not apply for us as all balconies are with in the unit area for us. However, air conditioner parts or hot water systems that have been installed next to units are now the unit owner’s to deal with for sure, regardless of who put them there or whether there was an approval in place.