Section 63-3022B, Idaho
Code Siding is not considered an energy efficiency upgrade. If a layer of insulation is placed beneath siding, the cost of the insulation is deductible if it otherwise qualifies. If the siding consists of an outer shell for protection against the weather and an inner layer of insulating material, the insulating material qualifies if the cost is separately identified by the seller.
Idaho Admin. Code r. 35.01.01.140