N.C. Gen. Stat. § 160D-1403.2

A local government may not assert before a board of adjustment or in any civil action the defense of estoppel as a result of actions by the landowner or permit applicant to proceed with development authorized by a development permit as defined in G.S. 143-755 if the landowner or permit applicant is challenging conditions that were imposed and not consented to in writing by a landowner or permit applicant.