under TCA97 s604 if a indivual has more then one residence, they may agree with the inspector or taxes which is to be treated as there main residence by giving notice to the inspector of taxes within two yrs of the beginning of the period of acquistion of the second residence, spouses living together may only have one main residence,
in the case of a married couple living together, relief may be claimed separately by each spouse in respect of dwellings house owned by that spouse and occupied by a dependent relative.