This is actually a pretty complex question that needs many more facts to be analyzed, including whether there is a Will, a probate estate, how long since father's death, does your sister have descendants, what are the other assets, etc. Please feel free to contact me to discuss. There is no charge for an initial phone consultation.

I agree with the answer given above. It is or can be a complex question. However, based on just the information you have provided, I can make the following simple assumptions: 1) Your brother wants to keep the house; 2) your sister wants nothing; 3) you want to be paid 1/3 of the equity value of the house assuming that your brother can get a new mortgage on the property or will be assuming the current mortgage.

You will need to pay for an apprisal of the property, determine the amount of the outstanding mortgage and determine the amount of the equity. Of that value, you are entitled to 1/3 regardless of your sister's position. Effectively, your sister is giving your brother a gift of her share. On the other hand, it would be nice of your brother to pay you for 1/2 of the value of your sister's share since you are effectively spliting the equity between the two of you.

OTOH, if the property is under water, you owe your brother nothing, nor, does he owe you anything since he will be taking over the mortgage and suffering whatever loss that represents.

Complex issues require complex answers. I have only given you a very simple one.

If your sister disclaims her interest in the house, you and your brother will each own 50%. You will need to negotiate with your brother for how to have him buy you out. You need an understanding of who will bear the burden of taxes, insurance and maintenance. How you and your brother will acquire your legal interests in the property is something for which you should get professional advice, and it will probably be worth paying for.