who pays for improvments?

Ok, I've found a place that looks great but it needs a little work. There is an area that with some work could be turned into an additional 6 privates, as of now its like brick walls, gravel floor and completly open... needs like half the walling done.

my quesiton is. How do I go about doing this? It is a rental. In your exp, those with exp, do you do the improvments and have the land lord pay some of it?

I don't want to put in all my money to improve the place... (probably only get a 3 year lease)

can anyone give me any idea how this sort of thing is generally done?

thanks