(a) A variance is a deviation from the minimum standards of the zoning ordinance and shall not involve permitting land uses that are otherwise prohibited in the zoning district nor shall it involve changing the zoning classifications of a parcel of land.
(b) The board of zoning appeals shall grant a variance to the zoning ordinance if it finds that the variance:
(1) Will not adversely affect the public health, safety or welfare, or the rights of adjacent property owners or residents;