I suggest you go to local planning office and read the relevant parts of the "local plan". This will show what the general feeling is for this land. If it's presently agricultural, you might be able to get a house on the land if you can show you need to live on site in order to run the smallholding, but there might be an agricultural restriction. This would devalue the land in an onward sale. By all measn talk to the planning officer, but read the plan first. Hope this helps.