Thanks for all the information Paul. I actually have little to no interest in moving banks at the moment. We only did it last year and it was so much hassle but there were errors that had to be sorted so I guess it should be easier. We only have around 7 and half years remaining on the mortgage so I'd be hoping if we made the over payment of 25k that would knock almost 3 more years off it. So I don't think I'd fix again for 5 years but rather 3 years.@Cathbarr As discussed in the other thread, your break fee should be zero at the moment, which you will get confirmation of from AIB shortly.
Technically, your biggest savings over the next five years would come from switching to KBC's five-year fixed rate (2.4% with €3,000 cashback) – savings of about €1,400 after fees and cashback. But I'm assuming you don't want to change lender. (Switching to KBC would also limit the amount you can overpay by.)
Because your break fee is zero, you can overpay by any amount without penalty. You don't have to break and re-fix to do this. But I would recommend asking AIB for an updated break fee just before you plan to make any overpayment, just in case it has increased.
Separately, you should also try to figure out if your BER really is B3 or higher. (Check if your property already has a BER cert.) Maybe look for old ads of recent house sales if your neighbours' houses are very similar to yours. Or ask your neighbours. A B3 or better rating would let you switch to AIB's 2.1% five-year fixed green rate. (But getting a BER assessment only to find your rating is less than B3 means that you would have wasted the money on the assessment.)
We made a 12k lump sum payment last year just before we fixed and it took on from 10 years to just over 8 and a half years.
In relation to the BER cert we don't have one. We built our home in 2011 and it wasn't a requirement back then so we would have to pay to get one done. Its also a detached bungalow in the countryside so there is nothing to go off from other neighbours. But I guess it is something we could consider. The savings would be minimal im guessing however due to the low balance of the mortgage but the money would be definitely better in my pocket than the banks. We just want to pay off our mortgage as quickly as possible now so every little helps and all that!!!