Section 137 (below) of the Act allows Owners Corproations to pass a by-law restricting the number of people in apartments to two adults per bedroom (it’s worded differently but that’s what it means). This would not cover your current situation but might be worth putting in place in case someone in the future decided to fill their apartment with bunk beds.
137 Occupancy limits
(1) A by-law may limit the number of adults who may reside in a lot by reference to the number of bedrooms of the residence.
(2) The limit may not be fewer than 2 adults per bedroom.
(3) The by-law has no effect:
(a) to the extent to which it is inconsistent with any planning approval or other law applicable to the lot, or
(b) in any other circumstances prescribed by the regulations for the purposes of this section.
(4) To avoid doubt, the Tribunal may make an order under Division 5 about a by-law made under this section.
(5) The regulations may provide for the circumstances when a person is a resident of a lot for the purposes of a by-law made under this section.
(6) For the purposes of this section, a “bedroom” is a room approved for use as a bedroom under, or indicated as a bedroom in any plans the subject of, a planning approval and includes any other room prescribed by the regulations as a bedroom for the purposes of this section.