I susect that some percentage of your portion of the gain may be assessable for CGT.
For example if you part owned and lived in it from the start of 2002 to the end of 2005*, then moved to another PPR and sold it at the end of this year (i.e. 6 years ownership 4 of which were owner occupied and the 12 months after vacating it being also exempt) then 1/6th or c. 17% of your portion of any gain is likely to be assessable for CGT.
But get professional advice if unsure.
* Just dealing in round years for simplicity but more detailed calculations will give more accurate results.