(1) Section 604A of the Principal Act is amended -

(a) in subsection (2)(b) by substituting "4 years" for "7 years",

(b) by inserting the following after subsection (2):

"(2A) Where a person disposes of land or buildings to which this section applies during the period beginning 4 years after the date they were acquired and ending 7 years after that date, any gain on the disposal of such land or buildings shall not be a chargeable gain.",

(c) in subsection (3) by substituting "Without prejudice to subsection (2A), on" for "On", and

(d) in subsection (4) -

(i) by substituting "subsection (2A) or (3)" for "subsection (3)",

(ii) in paragraph (a) by substituting "in the period from" for "in the period of 7 years from", and

(iii) in paragraph (b) by substituting "subsection (2A) or (3), as the case may be" for "subsection (3)".

(2) Subsection (1) applies to disposals made on or after 1 January 2018.