Assuming the property was purchased in joint names and that you didnt make any arrangements for a different split in the event of divorce then yes it would be fair to split it 50:50
However when my husband and I got divorced 5 years ago, I was earning a lot more than him so I decided to move out and sign my half over to him to counteract any maintenance I would otherwise pay for the children.
It really depends on how ammicable things are with your other half and whether either of you wants to stay in the house I suppose.