What do I do with an empty 15X15 room?

[David Brent]

I just closed on my first MF. 24 units. I have an empty shipping container in the back parking area, a 15X15 storage room w/ a boiler and some misc supplies, and an unused "office" perhaps 5x20.   The old owner stored a smattering of items (air filters, tile, etc. in them, but they are essentially unused and empty.  Meanwhile, only 5 of the 16 storage closets have been rented for $25/mos... and these are pretty terrible.  Maybe 3X2X6.   Any creative ideas (other than storage) on what to do to repurpose and rent?  This is C property.  The only thing I can think of is a value-add (free) tiny gym or maybe Bike storage room?   (The property is fully gated, and already has laundry room..)