In order to preserve the pattern of existing development, applicants shall be required to use a contextual front yard setback for primary uses and structures. Regardless of the minimum front yard setback in this chapter, applicants shall be permitted to use a contextual front setback. A contextual front setback may fall at any point between the front setback required in this chapter and the front setback that exists on a lot that is adjacent and oriented to the same street as the subject lot. If the subject lot is a corner lot, the contextual setback may fall at any point between the required front setback in this chapter and the front setback that exists on the lot that is abutting and oriented to the same street as the subject lot. If lots on either side of the subject lot are vacant, the setback shall be interpreted as the minimum required front setback that applies to the vacant lot. This provision shall not be construed as requiring a greater front setback than that imposed by the underlying zoning district, and it shall not be construed as allowing setbacks to be reduced to a level that results in right-of-way widths below established minimums.