The Board may grant a variance in a specific case and from a specific provision of any regulation, order or notice to appropriate conditions and provided the Board makes specific findings of fact based on evidence relating to the following:
(a) That there are practical difficulties or unnecessary hardships in carrying out the strict letter of any regulation, order or notice; and
(b) That the effect of the application of the provisions would be arbitrary in the specific case; and
(c) That an extension would not constitute an appropriate remedy for these practical difficulties or unnecessary hardships and this arbitrary effect and
(d) That such variance is in harmony with the general purpose and intent of the Board in securing the public health, safety and general welfare.