Every variance granted by the municipal agency shall be designed by said agency to safeguard the public health, safety, morals, and general welfare, and shall be further designed to provide reasonable consideration, among other things, to the character of the neighborhood or zone, the conservation of property values, the direction of building development in accordance with the Master Plan or portion thereof which has been adopted by the Planning Board, and shall not involve substantial detriment to the public good nor substantially impair the intent and purpose of this chapter, to the end that the spirit of this chapter shall be observed, public safety ensured and substantial justice done.