The short answer is yes, you are entitled to the equity investment. The long answer is that several questions need to be answered in order to evaluate the situation fully, like when was the house purchased, how long of a marriage, who will be living in the house, and how much money was put in during the marriage. Those are all questions that you should consult an attorney about.
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In making a property division, the court is going to consider what each person brought to the marriage. The longer your marriage, the less important pre-marital contributions are. However in your case, you not only made the investment to remodel, I presume marital funds went to pay the mortgage, real estate taxes etc. So the short answer is "yes" you are entitled to some equity. The question becomes, how much? I would contact an attorney and discuss your situation with her.
Marriage in Wisconsin is seen as an economic partnership. It is an equitable distribution partnership. The house is divisible marital property under Chapter 767, Wis. Stats. The fact is that you "made a big investment" in remodeling the house. Under normal conditions, it should have appreciated the home's value. You should be entitled to recoup money from the partnership including a share of the equity depending on the intent of any agreements you may have had. You need to consult with a lawyer immediately to protect your rights and to plan out an equitable division as too many questions still remain unanswered. There are law review articles online to start learning more.