I am in a similar position, but have received conflicting advice.
I bought house 10 years ago for 100k (incl stamp duty). It has been my main PPR since. It is now worth c.320k. We have gone sale agreed on another property.
I was told from one source that if I keep the house that I would have to pay CGT on the full amount since I first bought less allowances for indexation and renovations.
e.g. if indexation etc brought purchase price up to €170k, I would have to pay CGT of 30k when I sold once I rented. (320 - 170) = 150 @ 20% = €30k
Another souce gave the same information as you.
Assuming I sold in 5 years time and sale price was still 320 (again for calculation purposes), Scenario here would be (320 -100) = 220 *5/16*20% = €13,750.
Both sources were fairly adamant they were correct.
Please advise what is correct as this will help determine whether to keep the property for investment or whether to sell it.
Many Thanks