Under New York State law, although sole ownership before the marriage is an important factor, in determining whether a home is marital or separate property, the analysis does not end there. Courts in New York rule that separate property may lose its characteristic where there is a commingling of that property with marital funds. When sufficient commingling of the property exists, the separate property is deemed “contaminated,” and therefore marital property. Evidence of contamination of a home owned by one spouse before the marriage, according to New York case law, includes using marital funds to pay for the mortgage; improvements and renovations which increase the value of the property; and possibly funds used in maintaining or improving the property.
In a case where all of the above is present, a court in New York will almost certainly find the residence was contaminated which results in the property transforming from separate property to marital property. Once the property is determined to be marital property, the value of the residence is its current market value minus the market value of the property at the time of marriage.