in compliance with any applicable building code requirements. (c) Related costs Expenditures incurred by the taxpayer for— (1) any labor costs properly allocable to the onsite preparation, assembly, or original installation of the storm shelter, and (2) the certification described in subsection (b)(2)(C), shall be taken into account for purposes of subsection (a)(1). (d) Limitation (1) In general Subject to paragraph (2), an individual may not claim the credit allowed under subsection (a) more than once. (2) Joint return In the case of a joint return, the taxpayer may claim the credit allowed under subsection (a) unless the credit has previously been allowed to each individual filing such return. (e) Basis adjustments For purposes of this subtitle, if a credit is allowed under this section for any expenditure with respect to a storm shelter which is for use at a qualified residence, the increase in the basis of the qualified residence which would (but for this subsection) result from such expenditure shall be reduced by the amount of the credit so allowed. . (b) Conforming amendments (1) Section 6211(b)(4)(A) of the Internal Revenue Code of 1986 is amended by inserting 36A, after 36, . (2) The table of sections for subpart C of part IV of subchapter A of chapter 1 of such Code is amended by inserting after the item relating to section 36 the following new item: Sec. 36A. Storm shelter credit. . (c) Effective date The amendments made by this section shall apply to taxable years beginning after the date of the enactment of this Act.