Example. On July 1, 1999, Taxpayer A moves into a house that he owns and had rented to tenants since July 1, 1997. A took depreciation deductions totaling $14,000 for the period that he rented the property. After using the residence as his principal residence for 2 full years, A sells the property on August 1, 2001. A's gain realized from the sale is $40,000. A has no other section 1231 or capital gains or losses for 2001. Only $26,000 ($40,000 gain realized-$14,000 depreciation deductions) may be excluded under section 121. Under section 121(d)(6) and paragraph (d)(1) of this section, A must recognize $14,000 of the gain as unrecaptured section 1250 gain within the meaning of section 1(h).
Example 4 Separate dwelling unit converted to residential use. The facts are the same as in Example 3 except that in 2007 C incorporates the basement of the townhouse into his principal residence by eliminating the kitchen and building a new interior stairway to the upper floors. C uses all 3 floors of the townhouse as his principal residence for 2 full years and sells the townhouse in 2010, realizing a gain of $20,000. Under section 121(d)(6) and paragraph (d) of this section, C must recognize $2,000 of the gain as unrecaptured section 1250 gain within the meaning of section 1(h). Because C used the entire 3 floors of the townhouse as his principal residence for 2 of the 5 years preceding the sale of the property, C may exclude the remaining $18,000 of the gain from the sale of the house.
Example 5 Non-residential use within the dwelling unit, property depreciated. Taxpayer D, an attorney, buys a house in 2003. The house constitutes a single dwelling unit but D uses a portion of the house as a law office. D claims depreciation deductions of $2,000 during the period that she owns the house. D sells the house in 2006, realizing a gain of $13,000. D has no other section 1231 or capital gains or losses for 2006. Under section 121(d)(6) and paragraph (d) of this section, D must recognize $2,000 of the gain as unrecaptured section 1250 gain within the meaning of section 1(h). D may exclude the remaining $11,000 of the gain from the sale of her house because, under paragraph (e)(1) of this section, she is not required to allocate gain to the business use within the dwelling unit.
Example 6 Non-residential use within the dwelling unit, property not depreciated. The facts are the same as in Example 5, except that D is not entitled to claim any depreciation deductions with respect to her business use of the house. D may exclude $13,000 of the gain from the sale of her house because, under paragraph (e)(1) of this section, she is not required to allocate gain to the business use within the dwelling unit.
26 C.F.R. §1.121-1