Many thanks for all your responses.
The reason for the question was a comment in the NERI report that suggested that pension companies over-estimate what people need in their retirement in order to generate business. So for that reason, I wanted to get a feel for the average as opposed to for myself or an individual.
I realise that it will vary from person to person but I just wanted to get a feel for an average is that is possible.
I see from the threads that you linked, Sue Ellen, that a number of posters suggest €18k - €24k per year for a couple but as far as I could glean, this did not include one off costs such as replacing a car or exceptional medical expenses.
I also came across a report by TCD [broken link removed] which seems to indicate that the vast majority of pensioners have an income of €200 - €250 / week or or €10,400 - €13,000 per annum (per person).
From all of the above, I am inclined to believe that €12k + say €2k-5k for one off expenses would be a good baseline figure, per person per year.
Assuming (I know it is an assumption) that the state pension will cover ~€11k, the average pension needs to be €3k - €6k per year, increasing with inflation.
That's a lot less than I would have thought.