The petitioner had a house built in Wichita, Kansas and moved in to it in November of 2009. She had previously owned a different home in Wichita, but sold it in 2004 due to job issues and moved in with her daughter. In 2005, the petitioner resumed employment with her prior employer with her post of duty considered to by in California. In 2007, the petitioner bought a membership in an R.V. park in California and purchased a fifth-wheel (trailer) that was placed on a lot in the R.V. park. She lived in the trailer while working in California. On her 2009 return, the petitioner claimed a first-time homebuyer tax credit and IRS denied the credit due to the petitioner's ownership interest in and use of the trailer. The IRS also imposed an accuracy-related penalty. However, the court determined that the trailer did not meet the definition of "principal residence" under I.R.C. Sec. 36(c)(2) because the trailer was not "affixed" to the land under state (CA) law and, thus, did not meet the requirement of being a fixture under local law contained in Treas. Reg. Sec. 1.121-1(b)(1) (which governs for purposes of I.R.C. Sec. 36). Accordingly, the court allowed the first-time homebuyer tax credit. Oxford v. Comr., T.C. Sum. Op. 2014-80.