In GSTR 2003/3
90. Subsection 40-75(2) requires that for the period of at least 5 years the premises have been used only for making input taxed supplies under paragraph 40-35(1)(a). This requirement in subsection 40-75(2) is satisfied where the only supplies of the premises were by way of lease, hire or licence (i.e. residential rental) for any continuous period of at least 5 years between when the premises would otherwise have become new residential premises and when they are sold. See Example 8 at paragraphs 124 to 127.
92. However, a continuous period would not include periods when the premises are used for a private purpose or left vacant with no attempt to lease, hire or licence. See Example 9 at paragraphs 128 to 130.