Two parts of a building are "linked dwellings" if—
The common ownership condition is that—
(It does not matter whether or not the interests are held for the same title.)
If on a day in a chargeable period ("the day in question") two parts of a building constitute linked dwellings, this Part has effect in relation to the interests mentioned in paragraph (a) or (as the case may be) (b) of subsection (2) as if the two parts were, on the day in question, suitable for use as a single dwelling.
Subsection (3) does not apply if—
Those provisions are—
section 133 (property rental businesses);
section 134 (rental property: preparation for sale etc);
section 137 (dwellings opened to the public);
section 138 (property developers);
section 139 (property developers: exchange of dwellings);
section 141 (property traders);
section 143 (financial institutions acquiring dwellings in the course of lending);
section 144A (regulated home reversion plans);
section 145 (occupation by employees or partners of a qualifying trade or property rental business );
section 147A (caretaker flat owned by management company);
section 148 (farmhouses);
section 150 (providers of social housing).
The reference in subsection (2)(a) to a person connected with the company does not include a public body (as defined in section 153) or a body listed in section 154(2) (bodies established for national purposes).
If two dwellings in a building (dwelling A and dwelling B) are treated under this section as suitable for use as a single dwelling, and dwelling B and a third dwelling in the building ("dwelling C") are treated under this section as suitable for use as a single dwelling, all three are treated as suitable for use as a single dwelling (and so on).