Subsection (2) applies if on one or more days in a chargeable period—
a company is entitled to two or more single-dwelling interests in the same dwelling, or
two or more single-dwelling interests in the same dwelling are held for the purposes of the same collective investment scheme.
This Part has effect with respect to that chargeable period as if those separate interests constituted just one single-dwelling interest, the taxable value of which on any day is the sum of the taxable values of the separate interests.
In calculating the taxable values of the separate interests for the purposes of subsection (2), the market value of each interest is determined, under the provisions of TCGA 1992 applied by section 98(8), on the assumption that the other interest or interests are placed on the open market with that interest (on the valuation date appropriate to that interest).