Do I have to leave the house?

If you are married, then generally what will happen to the house will ultimately be resolved as part of a financial settlement within the divorce. 

Your Solicitor would advise you as to this in more detail depending upon the circumstances of your case, but ultimately it may be that the house is sold in order for the proceedings to be divided in some manner, or sometimes one party will buy out the other's interest in the property. 

There is not generally a requirement to vacate the house until a financial settlement is agreed. 

If, however, one party is violent or threatening to the other, then the other may seek a Court Order to occupy the house to the exclusion of the party who has been violent or threatening for a period of time.