Uniform Capitalization

"The uniform capitalization (UNICAP) rules require the capitalization of all direct costs and certain indirect costs properly allocable to real property and tangible personal property produced by the taxpayer. For purposes of the uniform capitalization rules, to "produce" means to construct, build, install, manufacture, develop, improve, create, raise or grow [§ 263A(g)(1); Treas. Reg. § 1.263A-2(a)(1)(i)]. Self-constructed assets and property built under contract are treated as property "produced" by the taxpayer and the rules under IRC § 263A(a) govern."

"In addition, § 263A(f) requires the capitalization of interest expense when the taxpayer produces certain property. The interest capitalization rules under Treas. Reg. § 1.263A-8 contain precise definitions of designated property and include inherently permanent structures in the definition of real property. In summary, all real property and certain tangible personal property are subject to the interest capitalization rules. Therefore, any change in the allocation of costs between real and tangible personal property may have an impact on the amount of capitalized interest."

http://www.irs.gov/Businesses/Cost-Segregation-Audit-Technique-Guide---Chapter-6.1-Uniform-Capitalization