A couple of days ago, I met with an individual who listed his marital status as separated but then he wrote in that he was not legally separated. When I asked him about it, he told me that they weren't living together but they hadn't done any paperwork so it wasn't a legal separation. This is one of the most common misconceptions that I hear about the divorce process in Virginia.
You don't have to do any paperwork to be legally separated in Virginia. All that is required is that you being living separate and apart and one of you intends to end the marriage. You don't even have to have mutual consent to end the marriage, only one of you has to decide that the marriage is over.
If you are separating with the intention of ending the marriage, you should make sure that you advise someone, besides your spouse, that you do intend to seek a divorce. When you go through the divorce process, you will have to have a witness who can testify that you have been separated for the required time period and that it was your intent to end the marriage. I have seen Judges ask the witness "How do you know that it was this person's intent to end the marriage?" There is no better answer than "He/She told me that the marriage was over".
Since you also have to be living separate and apart, the next question is can they have be living separate and apart while in the same house. This can be very difficult to prove to the Court. I have seen Judges tell someone who was seeking a divorce that they were going to have to provide a lot more evidence than just someone's testimony to prove that the couple was actually separated while living in the same house. As a minimum, you have to have separate bank accounts and have some type of arrangement for the household bills. You must be able to show the court that you are maintaining completely independent lives while living in the same house. I always advise people who tell me that they want to continue living in the same house but are living separate and apart in the house, that one of them needs to move out. After all, you don't intend to continue living together after the divorce is finalized so start the process now.