Renting property storage on Spacer.com.au

Have any members had any experience with renting out storage or sheds as part of a property?
(either on the website Self Storage | Rent Space & Cheap Storage | Spacer or self-organised?)

I'm considering doing this separate to my IP as the tenants do not use 2 storage sheds and could generate extra cashflow for me..

 

They are pretty good at hiding their fee other that to say it is minor. Not sure ~20% is minor

 

If the storage shed are within the leased premises the tenants have a right to quiet enjoyment to use / not use the sheds. You cant allow others to use their property.

 

The tenants can deny access - they are renting the entire property.
How do you know they are not using the sheds, even if occasionally?

 

I do this, however the sheds are fenced off rest of the rental property, with separate access and it is made clear that it is not part of the lease.

I don't use any service, just advertise on Gumtree and use a short lease that I made up (not the standard residential one).