The R-1, R-2, R-3 & R-6 Residential Zoning Districts have a front yard setback requirement of 30' or average existing dwelling setback, whichever is greater.  When a proposed modification to a home involves the front of the structure (such as adding or enclosing a front porch) it is necessary to submit the existing front yard setbacks of the houses located on the sames side of the street and within the same city block as the structure to be modified.  It is best to use a common point (such as the back side of the city sidewalk) and measure to the enclosed living space of each principal structure.  For example, if there is an open porch, you would measure to the back wall of the open porch.  Once the measurements are submitted, the Zoning Officer will determine if the proposed addition and/or modification would encroach into the required setback.  All variance requests are subject to review and approval by the Board of Zoning Appeals.