A couple has to be four years living apart in the preceding 5 years in order to obtain a divorce. In certain circumstances parties can be residing in the same property but living apart and may accordingly qualify. This is something on which you should consult a family law specialist. There are not other grounds necessary to qualify for a divorce however the court must be satisfied that “proper provision” has been made for both parties and their children before they will rule terms of divorce. Practically speaking this does mean a hearing of some sort before a judge of the Circuit or High Court. If all matters are, however, agreed between you and your spouse, the formal hearing is usually reasonably short.
Generally if you have a separation agreement or order you will want to get your divorce with the minimum of fuss however, in theory either party can reapply to the court to reopen financial or other matters on divorce. There may be reasonable grounds for such an application but this is a difficult application to make and careful legal consideration would have to be given to this matter. Unless there are very substantial grounds the courts are not inclined to visit the same matters twice in a relatively short space of time.