The provisions of this Article shall not be applicable with respect to any items purchased for the purpose of fulfilling a real property contract for a capital improvement entered into or awarded, or entered into or awarded pursuant to any bid made, before the effective date of the tax imposed by a taxing county when, absent the provisions of this section, the items would otherwise be subject to tax under the provisions of this Article.
N.C. Gen. Stat. § 105-468.1