§ 255-173.   Powers and duties.
The Board shall have the following powers:
   A.   Appeals and interpretations. To hear and decide appeals where it is alleged that there is an error in any order, requirement, decision or determination made by any administrative official in the enforcement of said Act or of this chapter adopted pursuant thereto. To interpret upon the words, terms, rules, regulations, provisions and restrictions of this chapter where there is doubt as to the meaning thereof, including determination in specific instances whether questionable are permitted by virtue of being similar to or customarily incidental to permitted as provided by this chapter.
   B.    . To hear and decide to the terms of this chapter in such cases as are herein expressly provided for, in harmony with the general purpose and intent of this chapter with power to impose appropriate conditions and safeguards.
   C.   Variances. To authorize, upon appeal, in special cases such variance from the terms of this chapter as the Board shall feel will not be contrary to the public interest, where, owing to special conditions, a literal enforcement of the provisions of this chapter will result in unnecessary hardship and so that the spirit of this chapter shall be observed and justice done. The special circumstances requiring a variance shall be fully set forth in the minutes of the Board, which shall show the vote of each member upon each question.