How does leased land effect the sale of a single family home?

[Allison Meggison]

I searched some other posts but it seems like I just need to get the details of the lease? I found a seller in Maine who has a Single family home on a 7,405 sq ft lot, half the lot is empty from where an older house was torn down. The homeowner said he pays $250 a month for the lot rent because it's leased land. He said that in order for the land to be built on it would have to be bought and rezoned. How do I account for this when making an offer on the house?