In exercising the powers granted by RCW 36.70.810 and 36.70.820, the board of adjustment may, in conformity with this chapter, reverse or affirm, wholly or in part, or may modify the order, requirement, decision or determination appealed from, and may make such order, requirement, decision or determination as should be made and, to that end, shall have all the powers of the officer from whom the appeal is taken, insofar as the decision on the particular issue is concerned.