Taxes Consolidation Act 1997 section 604

Disposals of principal private residence

Section 604 exempts from capital gains tax the gain made by an individual on the disposal of a dwelling house (or part of a dwelling house) which has been occupied as the individual's only or main residence, together with gardens or grounds of up to one acre.

• A gain on the disposal of your principal private residence is fully exempt from CGT provided you occupied the residence (or are deemed to have occupied it) throughout your period of ownership; the last 12 months of ownership are always treated as a period of occupation
• Where the residence was not occupied throughout the full period of ownership, only a proportionate part of the gain is exempt, calculated by reference to the ratio of the period of occupation (including the final 12 months) to the total period of ownership
• Certain periods of absence are treated as periods of occupation, including any period working abroad and up to four years of enforced absence due to the location of your workplace or a condition of your employment requiring you to live elsewhere, provided the residence was occupied both before and after each absence
• The relief is restricted where part of the residence was used exclusively for business purposes, where the disposal involves development land, where the residence was acquired mainly to realise a gain, or where the residence is disposed of by way of a lottery or raffle for more than its market value

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