Determination of use during periods of out-of-residence care

becomes physically or mentally incapable of self-care, and

owns property and uses such property as the taxpayer’s principal residence during the 5-year period described in subsection (a) for periods aggregating at least 1 year,

then the taxpayer shall be treated as using such property as the taxpayer’s principal residence during any time during such 5-year period in which the taxpayer owns the property and resides in any facility (including a nursing home) licensed by a State or political subdivision to care for an individual in the taxpayer’s condition.