Where there are practical difficulties or unnecessary hardship in the way of carrying out the strict letter of the requirements of this chapter, the Board of Appeals shall have the power in passing upon appeals to vary or modify the application of any of the regulations of this chapter relating to the use, construction or alteration of buildings or structures, or the use of land, so that the spirit of the chapter shall be observed, public safety and welfare secured and substantial justice done. No variance in the strict application of this chapter shall be granted by the Board of Appeals, unless it finds that each of the following facts and conditions exist:
(a) That there are special circumstances or conditions fully described in the findings of the Board applying to such land or buildings and not applying generally to land or buildings in the neighborhood, and that said circumstances or conditions are such that strict application of the provisions of this chapter would deprive the applicant of the reasonable use of such land or buildings.
(b) That, for reasons fully set forth in the findings of the Board, the granting of the variance is necessary for the reasonable use of the land or building and that the variance as granted by the Board is the minimum variance that will accomplish this purpose.
(c) That the granting of the variance will be in harmony with the general purpose and intent of this chapter and will not be injurious to the neighborhood or otherwise detrimental to the public welfare.