Hi Mr Leone,
Thanks for your enquiry.
If your Father did not leave a Will, then his Estate is distributed in accordance with the strict rules of Intestacy (the rules pertaining to where someone dies without making a Will).
Under these Rules, your Mother would have been entitled to the first £250,000 worth of your Father's assets, to include the property.
If his Estate, including the house were valued at over £250,000 then you and your brother are entitled to the following-
Your Mother receives the first £250,000. Any monies over this amount are distributed so your Mother receives a life interest in half of whatever is left over
Therefore if your Father left £250,000 or less, you are not entitled to anything.
I hope this has assisted you and answered your question.
Please let me know if you require any further clarification.