Consideration of variance. In consideration of all appeals and all proposed variations from the terms and requirements of this chapter, the ZBA shall, before making any variation from the chapter in a specific case, first determine that the proposed variation, or a lesser variance from the terms of this chapter, will not impair an adequate supply of light and air to adjacent property, or unreasonably increase the congestion in public streets, or increase the danger of fire or endanger the public safety, or unreasonably diminish or impair established property values within the surrounding area, or in any other respect impair the public health, safety or welfare of the inhabitants of the Township. The concurring vote of the majority of the members of the Board shall be necessary to reverse any order, requirements, decision or determination of the Zoning Administrator, or to decide in favor of the applicant any matter upon which it is authorized by this chapter to render a decision.