I am not sure what the issue here is. They gave you a loan to buy the house in which you lived. You told them that you would be living in it. Therefore it is a home loan under the Mortgage Arrears Code and for tax purposes. It does not matter whether it is ACC's normal practice or not.
So they got a Judgement against us and are now looking to have a repossession order put on our home
Whether it is a home loan or a commercial loan, it is irrelevant. They are entitled to get a repossession order if you default on the loan. I don't know why they had to get a judgment? Usually, one only gets a judgment if the loan is not secured.
So, is it possible that they gave you an unsecured loan? If so, now they have a judgment, the next stage would be to convert this into a judgment mortgage. However, they are still covered by the Mortgage Arrears Code and you should bring this to their attention.
When you took out the loan, did you use a solicitor? What did that solicitor advise? What is that solicitor advising now?
It is important to recognise as early as possible if your loan is not sustainable. If there is no likelihood that you will be able to pay the loan, then maybe you should consider surrendering the house? If you do this, you should seek something from them in return. For example, that they will write off any deficit remaining after the house is sold.
Brendan