6.— A residential property shall not, for the purposes of this Act, be regarded F13[as a relevant residential property in relation to the liability dates in the years 2013 to 2020] where the property—

(a) has been completed but not sold by the person who has constructed the property, or who has had the property constructed,

(b) is not occupied as a dwelling,

(c) has produced no income that would be chargeable to income tax or corporation tax, as the case may be, under Case I, Case IV or Case V, as the case may be, of Schedule D (within the meaning of section 18 of the Act of 1997), and

(d) is trading stock (within the meaning of section 89 of the Act of 1997) of the person referred to in paragraph (a).