(1) An individual taxpayer may deduct from taxable income an amount actually paid or accrued by the individual taxpayer during the taxable year for the actual installation of energy efficiency upgrade measures within any existing residence. As used in this section, "existing residence" means any residence in the state of Idaho that serves as the primary place of residence of the individual taxpayer in being, under construction, or subject to an outstanding legal building permit on or before January 1, 2002.
(2)  As used in this section:
(a)  "Energy efficiency upgrade measure" means an energy efficiency improvement to the building envelope or duct system that meets or exceeds the minimum value for the improved component established by the version of the international energy conservation code (IECC) in effect in Idaho during the taxable year in which the improvement is made or accrued.
(b)  "Energy efficiency upgrade measure" includes:
(i)  Insulation that shall be added to existing insulation not in replacement of existing insulation;
(ii)  Windows that may replace less efficient existing windows;
(iii)  Storm windows;
(iv)  Weather stripping and caulking; and
(v)  Duct sealing and insulation. Duct sealing requires mechanical fastening of joints and mastic sealant.