if this does not include land, it is not real estate. Must be personal property?
NO!
The house is attached to the land it is real estate by definition.
You are appraising the divided interest of the entire property, as this building only, separate, from the overall real estate.
Your subject property is house X described by the tax assessor's property record card, excluding land and the balance of the property.
Your value is most likely "value in use", or use value, as it most likely can not be sold without the land, and depending on construction may not be movable (note, there are some homes that do get moved) as a residence, assuming continued rights of ingress and egress over the land to the house,