Lot's of times we are running out of barn space and need to make an appropriate decisions based on the free barn space.
It will be very helpful to add a kind of icon (maybe it will function as a shortcut to barn), just like the one that appears when
something is being added to barn.
The icon can have some numbers like 670/700 which indicates the total number of goods in the barn relatively to the overall space.
Or it can just show the free space instead.