I just moved into a new apartment where the utility closet is accessed from the hallway with a separate key instead of being located inside the apartment. Every unit has their own exclusive utility closet; they are not shared between tenants. It contains things such as the hot water heater and gas meter. I do not have a key to this closet, and maintenance won't give me one.

I have used extra space in my utility closet for storage in my past apartments, and would like to do that here as well. In this case, there is a small on-demand water heater instead of a large cylinder, which leaves a large amount of unused space, perfect for storage.

Is my property allowed to deny me access to my own utility closet?