The IRS has a definition and examples of what is a "main home".
DEFINITION of 'Main Home' A term used by the Internal Revenue Service (IRS) to define the home a taxpayer has lived in most of the time during a given taxation year, or the only home a taxpayer owns. The classification of a taxpayer's main home is important when considering gains resulting from the sale of a main home.
This section explains the term “main home.” Usually, the home you live in most of the time is your main home and can be a:
To exclude gain under the rules of this chapter, you in most cases must have owned and lived in the property as your main home for at least 2 years during the 5-year period ending on the date of sale.
Land. If you sell the land on which your main home is located, but not the house itself, you cannot exclude any gain you have from the sale of the land. However, if you sell vacant land used as part of your main home and that is adjacent to it, you may be able to exclude the gain from the sale under certain circumstances. See Pub. 523 for more information.
Example.
You buy a piece of land and move your main home to it. Then you sell the land on which your main home was located. This sale is not considered a sale of your main home, and you cannot exclude any gain on the sale of the land.
More than one home. If you have more than one home, you can exclude gain only from the sale of your main home. You must include in income gain from the sale of any other home. If you have two homes and live in both of them, your main home is ordinarily the one you live in most of the time during the year.
Example 1.
You own two homes, one in New York and one in Florida. From 2012 through 2016, you live in the New York home for 7 months and in the Florida residence for 5 months of each year. In the absence of facts and circumstances indicating otherwise, the New York home is your main home. You would be eligible to exclude the gain from the sale of the New York home but not of the Florida home in 2016.
Example 2.
You own a house, but you live in another house that you rent. The rented house is your main home.
Example 3.
You own two homes, one in Virginia and one in New Hampshire. In 2012 and 2013, you lived in the Virginia home. In 2014 and 2015, you lived in the New Hampshire home. In 2016, you lived again in the Virginia home. Your main home in 2012, 2013, and 2016 is the Virginia home. Your main home in 2014 and 2015 is the New Hampshire home. You would be eligible to exclude gain from the sale of either home (but not both) in 2016.
