The home is a marital asset. The monies you used to purchase the home, including the downpayment, although separate property, was converted to marital property upon it's use to purchase a marital asset. You both own 50% of the home.
New York is an "equitable distribution" state. Separate property, including property acquired before a marriage and any gifts or inheritances whenever acquired, is to remain with the spouse who owns it. Separate property also includes any increase in value or property acquired in exchange for separate property.
Marital property is defined as "all property acquired by either or both spouses during the marriage and before the execution of a separation agreement or the commencement of a matrimonial action, regardless of the form in which title is held, except as otherwise provided in agreement pursuant to subdivision three of this part. Marital property shall not include separate property as hereinafter defined."
The key factor in New York is when the 'matrimonial action' is begun and what is defined as 'matrimonial action' for purposes of ceasing the accumulation of 'marital property'.
In Anglin v. Anglin, [FN5] the plaintiff commenced a separation action against defendant in 1982, which was not disposed of until January 1988 when the parties stipulated to the entry of a judgment of separation. Twenty months after entry of the judgment, the plaintiff brought an action for divorce pursuant to DRL 170(5). The Third Department affirmed an order of Supreme Court ruling that all property acquired by either party up to the commencement of the divorce action was marital property. It held that the commencement of plaintiffs' prior separation action was not "a matrimonial action" for purposes of the definition of marital property under DRL 236[1][c].
McMahon v. McMahon