It is fundamental for the purpose of this chapter to recognize that some existing lots in the Village are more difficult to use for the intended purpose because of location, size, slope or general topography. Usually such differences will not make use of a lot impractical, although such use may require greater expense or ingenuity. Where such lots cannot practically be used for a permitted use, the remedy of variance is available to permit modifications in yard or other requirements to make possible a use generally permitted in the district, but not to permit a more intensive use. Difficulty in using land for a permitted dwelling because of topography problems should not justify use of the land for a commercial use not normally permitted but should justify only accommodation in the regulations so as to facilitate a dwelling.