I should clarify my point, and BTW, I agree with all the posters above.
Your father owns two houses, house A which is his PPR and house B which is not.
He wants to will or gift you house B, and do this in a way that legally minimizes the tax bill for both of you.
If he disposes of house B, while he is alive, either by selling or gifting, he will be liable for CGT if the value has increased in the time that he has owned it.
If he wills this house to you, there will be no CGT liability whn he dies and you inherit, regardless of any increase in value.
If he gifts or wills the house to you, you are liable for Capital Acquisition Tax (CAT), unless the value of the gift is less than the threshold for parent to child gifts.
There are excemptions to this, in certain circumstances, if you live in the house for 3 years and gifts and inheritancesd are treated differently for these exemptions.
However, if you read the line I quoted above, it is more complex that I realised and I am not an Accountant, so best to get some expert advice.
In your last post, you said that you would be looking after your father in house B, but house A would be his PPR. Not sure what you mean. Which house is he currently living in ?