N.C. Gen. Stat. § 54B-181

A State association may invest in real property and equipment necessary for the conduct of its business and in real property to be held for its future use. Such association may invest in an office building or buildings, and appurtenances for the purpose of the transaction of such association's business or for rental. No such investment may be made without the prior written approval of the Commissioner of Banks if the total amount of such investments exceeds the association's net worth.