That there are practical difficulties in complying with the requirements of this chapter with respect to the dimensional characteristics of a lot or parcel of land, a building or structure, or any of them in combination, because of exceptional or extraordinary physical conditions involving land, a building or structure, or any of them. A practical difficulty resulting from an exceptional or extraordinary condition may include, for example, the exceptional narrowness, shallowness, shape or area of land; exceptional conditions in the elevations of land; the presence of unbuildable areas, such as wetlands or a floodplain; or other exceptional or extraordinary physical condition of the land or a building or structure.