I'm most familiar with Community Property States, but I'll give you a few things to think about until you get an Attorney in Iowa. (Which you NEED)
Iowa has the equitable distribution method which basically means that the court will try to divide the marital assets in a fair and equitable manner between the spouses. Marital property subject to equitable division is that which comes from your employment and investments of you and your wife during the marriage. Equitable division does not mean the Judge will divide your marital property equally. It will be divided by the Judge in a way that results in a fair or equitable result for each spouse. The Judge will consider the contribution of each party to the marital estate; the earning capacity of each party; the age of each spouse; the desirability of awarding the family home or the right to live in the family home for a reasonable period to the party having custody of the children; the economic status of each party and; Other economic circumstances of each party. Non-marital property or property defined as property acquired by one spouse prior to the marriage or property acquired by on spouse by gift, inheritance, bequest or devise, even though during the marriage, remains that spouse's separate property is not subject to equitable division.
Your house is a tricky one. If the down payment came from a source of money earned prior to marriage or by gift/inheritance then that portion of the house could be be just yours. The payment that you made on the mortgage during the marriage most likely will fall under the equitable distribution rule and your wife may be entitled to that portion. You could even come to a settlement agreement and buy your wife's portion from her. You don't need to play around with this one.....break out the ole check book and hire an Attorney