The apartment has a kitchen where JC can take food from Jock's fridge. Jock is never seen in his apartment, and is best used by the JC as a safe house.
JC can make the jump from the windows in Maggie Chow's apartment living room to Jock's balcony.
The elevator shaft in the apartment complex contains a dead-end crawl space with a human skull placed inside and a button, which opens a hatch below to the street - the point of this is to avoid a certain dead-end situation which can occur if, when the elevator is upstairs, JC gets in the shaft, pushes the button to go down, quickly runs backwards to get out of the elevator before it starts descending and then quickly runs forwards again on top of the now descending elevator. The only way out of this situation is to use the aforementioned hatch.