We need the precise terms of the ownership of the house , there have been many questions on this subject on AB. It may well be that you have the right to live in the house and so your fathers share would be virtually worthless as all it would consist of is 1/2 a house minus the £35,000 , but with a tenant who has the right to live there for life (you) . If that is the case your fathers share is worth very little as it could not be sold with out your permission. It is also possible that your fathers share is already automatically left to you on his death under the terms of the original will. If this is the case ,( and it may very well be,) your father effectively has nothing to leave to anyone. You have to get a solicitor to look at the terms of the will and the ownership of the house, only when you know that can we advise you futher.