I don't know why AIB would allow you to sell the apartment and keep the mortgage at all. You have the cash, so if you sell it, you should pay off your mortgage shortfall in full. It makes little financial sense to have money on deposit at 1% while paying 4.4% on a loan of a similar amount.
Why did you need to move out of an apartment worth €350k for the children?
It must be a fair sized apartment if it's worth €350k.
It might make sense to move back into the apartment , pay down the loan and start building up a deposit again. Not ideal, but it makes great financial sense.
How much would a house in the area you want suitable for your children cost?
This is a key question.
Option 1 - Consider keeping the investment property
Think of it as two loans - one the value of the home and the other for the negative equity.
Rent received| €1,625 |
Interest cost| €1,300 |€350k@4.4%/12
profit before costs|€300
So this is a profitable investment based on the current value. But probably not profitable enough to retain it.
You are repaying around €800 capital every month, so you are gradually paying down this mortgage.
Option 2 - You could apply for a negative equity mortgage
Sales proceeds €350k + cash €160k = around €500k to buy a house
You should be able to meet the repayments.
Have you asked the bank for this?
Option 3 - you could apply for a mortgage to buy your new house and keep the old house
You have €160,000, so how much do you need to borrow? It will be difficult if you already have a mortgage but check with them anyway.
Option 4 - just sell the apartment and rent
There is nothing at all wrong with this option.
Financially you are better off moving back into your former home and buying a new property when you can afford to do so. But if you don't want to do so, then you are better off renting.