“(2) A transaction is within this sub-paragraph if its main subject- matter consists of— (a) an interest in at least two dwellings, or (b) an interest in at least two dwellings and other property.”
“(2) A building or part of a building counts as a dwelling if— (a) it is used or suitable for use as a single dwelling, or (b) it is in the process of being constructed or adapted for such use.”