- 5 - Inc. v. Commissioner, 503 U.S. 79, 84 (1992); Welch v. Helvering, 290 U.S. 111, 115 (1933). Generally, section 280A(a) prohibits deductions allocable to the business use of a “dwelling unit” used by a taxpayer during the taxable year as a personal residence. However, if a portion of the dwelling unit is used as a taxpayer’s principal place of business, deductions allocable to that use are permitted, though they are limited if the gross income from the business use is less than the total business expenses. Sec. 280A(c)(1), (5). Here, petitioners had insufficient gross income from their woodworking business in 2001, 2002, and 2003 to offset deductions for either the furnace or the workshop after the application of section 280A(c)(5). Respondent does not dispute the Wyoming workshop was used as petitioners’ principal place of business with respect to their woodworking business. The issue is simply whether the garage- turned-workshop should be considered part of the Wyoming residence and thus be subject to the home office limitations of section 280A. Notably, the workshop was attached to the house, and petitioners used its entrance to gain access to the residence in the winter. Aside from common sense--an attached garage is considered part of one’s home under normal circumstances--caselaw has held that even a detached office building located on the samePage: Previous 1 2 3 4 5 6 7 8 9 10 NextLast modified: March 27, 2008