b

the building or structure were brought into qualifying use, for the purposes of the allowance in relation to the contribution, on—

i

the day on which R first brought the building or structure into qualifying use, or

ii

if R is a public body, the earlier of the day mentioned in sub-paragraph (i) and the day on which R first brought the building or structure into non-residential use.

4

If, at any time in the period beginning with the day on which C made the contribution and ending with the day on which R first brought the building or structure into non-residential use, C did not have a relevant interest in the building or structure—

a

C is to be treated for the purposes of allowances under Part 2A as having had a relevant interest in the building or structure when that period begins, and

b

C is not to be treated for those purposes as ceasing to have that interest on any subsequent sale of R's relevant interest in the building or structure.

7

In determining, for the purposes of this section, the day on which R first brings a building or structure into non-residential use, ignore any use of the building or structure which is insignificant.