Parties are separated when they stop living as husband and wife. This can happen when one party moves out of the former matrimonial home or the parties can be separated under the one roof provided certain requirements are met and you can establish to the Court that you both live separate lives
To prove that you have been separated under the one roof you will need an affidavit from at least one independent witness who can testify as to your living arrangements. You will also need to file an affidavit providing evidence as to such arrangements.
If the separation is disputed, the court compares your living arrangements before separation to after separation. For example, the court looks at things which may go to make up the marriage like sleeping arrangements, performance of household services, absence of shared activities, parties ceasing to hold themselves out as a couple, lack of sexual relations between the parties, and the financial arrangements of the parties.