Divorce

You probably do need a post-nuptial agreement under the cicumstances.Because he purchased the home in his sole name before your marriage, it is most likely his separate property.  Since you contributed 50/50 and invested a great deal in improvements, you most likely would like to be compensated for your contribution and investment.  It's unclear whether your contribution and investment was made before or after your marriage.  If the latter, it is unclear whether your contribution and investment was made with community funds or your separate funds.  It is also unclear whether if property is being used as your marital homestead or is rented out.Since you did not address these issues in a premarital agreement, you probably should address them in a post-nuptial agreement.  Since you don't want the house, you should come up with a reasonable amount to compensate you for your contribution and investment, and a reasonable and fair way to insure that you receive such compensation.Similarly, any retirement benefits which accrued as a result of his work before your marriage is his separate property.  If he continued to woek after your marriage, that portion of any retirement would be community property.  Retirement benefits complicate divorces, may require a QUADRO, have tax implications, and usually require an experienced divorce attorney.  If he is relatively young and still working, you should come up with some sort of reasonable compensation for any community interest that may accumulate in his retirement account.  That can reduce the amount you may have to pay if you divorce to an attorney.