"[Part I] of this Act shall have effect confer on a tenant of a leasehold house, occupying the house as his residence, a right to acquire on fair terms the freehold or an extended lease of the house and premises where- (a) his tenancy is a long tenancy at a low rent and the rateable value of the house and premises [is below certain limits]; and (b) at…the time when he gives notice in accordance with this Act of his desire to have the freehold or to have an extended lease…he has been tenant of the house under a long tenancy at a low rent, and occupying it as his residence, for the last 5 years or for periods amounting to 5 years in the last 10 years…"
"…'house' includes any building designed or adapted for living in and reasonably so called, notwithstanding that the building is not structurally detached, or was or is not solely designed or adapted for living in, or is divided horizontally into flats or maisonettes: and- a) where a building is divided horizontally, the flats or other units into which it is so divided are not separate 'houses' although the building as a whole may be: and b) where a building is divided vertically the building as a whole is not a 'house' though any of the units into which it is divided may be."