She specifically says that Nikola is borrowing the building; not the land. It would be within the agreement to move the whole building at some future time and get a new one built on the plot. It might actually be preferable for the goblin with how long Nikola might live."Free? Nah, don't talk daft. I'll build the buildin', an' you'll borrow it from me. I'll just take it back when you're six feet under an' I get to lodge there."