CG64390 - Private residence relief: garden and grounds: ownership: differing interests in dwelling-house and land
It may also be the case that the interest which a person has in some or all of the land is not the same as the interest that they have in the dwelling-house. For example, a person may own the freehold of the dwelling-house and a 20 year lease on a neighbouring plot of land which is used as part of the grounds of the house.
If the other conditions for relief are fulfilled, relief will be available on a disposal of the land.