In exercising any of the powers listed in this article, the board of adjustment may, so long as the action is in conformity with this chapter, reverse or affirm, wholly or partly, or may modify the order, requirement, decision or determination appealed from and may make such order, requirement, decision or determination as should be made and to that end shall have all of the powers of the building official from whom the appeal was taken. The concurring vote of four members of the board of adjustment shall be necessary to reverse any order, requirement, decision or determination of the building official or to decide in favor of the applicant on any matter upon which it is required to pass under this chapter or to effect any variation in the application of this chapter.