Okay - if you have your formal loan offer then you can go ahead and sign contracts.
If there were conditions on the formal loan offer (e.g. life insurance, house insurance, more bank statements) these have to be fulfilled before Bank of Ireland will advance the mortgage monies. You may have already sent in some of these items and these are waiting in a queue in head office for someone to look over them and validate that they're happy with what you've sent in. But you don't need to fulfil all the conditions until shortly before you're ready to close and move in.