In this Part, owner in relation to a dwelling, a sole‑occupancy unit or a building means—
(a)
in the case of a dwelling, sole‑occupancy unit or a building being purchased under a terms contract (within the meaning of the Sale of Land Act 1962) under which the purchaser has become entitled to possession or to the receipt of the rents and profits, the purchaser of that dwelling, sole‑occupancy unit or building; and
(b)
in the case of any other dwelling, sole‑occupancy unit or building, the owner of that dwelling, sole‑occupancy unit or building.