Legal Question in Wills and Trusts in Connecticut

First of all, I'm not sure why your understanding is that the person with the life estate is responsible for the taxes, insurance and the upkeep of the home. However, it does make sense that that person should pay those expenses because he/she is using the home.

Is there a will that you are referring to? If so, I would need clarification as to what the will says. It appears from your question that the decedent gave you a life estate in a home and if you decided you no longer wanted to live in the home, you would have to sell it and share the proceeds 50/50 with your sibling. If the will does not state that you get a credit for the expenses you paid on the home, then my guess is, no, they are not subtracted from the net proceeds upon sale.