From Mecklenburg County Code Enforcement:
It has recently come to our attention that setbacks are being measured for all buildings the same, which is not the case for Accessory Buildings (i.e. Garages, Accessory Buildings and Accessory Dwelling Units) compared to the measuring of setbacks for principal dwelling structures.
In an attempt to clarify where setbacks are to be measured, we are providing the code sections below directly from the City of Charlotte Zoning Ordinance. I have also included information regarding the allowance of mechanical equipment only a limited amount of setback encroachment and this applies to all structures. This applies to all construction within the City of Charlotte zoning jurisdiction.
DWELLING STRUCTURES (Principal Residence) Setbacks are to be measured from the property line, or from back of curb, depending on the information listed on the permit in the NOTES section. (See 12.106(5) below)
ACCESSORY BUILDINGS (Garages, Accessory Buildings, Accessory Dwelling Units) Setbacks are measured from the property line to the most extreme architecture feature of the structure, usually a eave overhang. (See 12.106(2)(a) below)
Section 12.106. Uses and structures prohibited and allowed in required setbacks and yards.
(1) No principal building or principal structure shall be located within any setback or yard required by these regulations except as provided in this Section and elsewhere in these regulations.
Petition No. 2002-13, § 12.106(2), 4/15/02)
(2) (a) No accessory structures, including architectural features, as cited in five (5) below, shall be located within any setback or side yard required of these regulations, or located within three (3) feet of a lot line in the established rear yard. No accessory structure shall be located within any established setback in any residential district, except as otherwise provided. If an accessory structure exceeds a height of 24 feet in the single-family, multi-family, urban residential and mixed use districts, it must be located at least 15 feet from the rear and side property lines. In all zoning districts, except as provided for in Section 12.108, if the accessory structure exceeds the height of the principal structure, it must meet the minimum side yard of the principal structure and be located at least 15 feet from the rear property line. In addition, no accessory structure, excluding the square footage of an accessory dwelling unit shall exceed the total square footage of the heated area located on the first floor of the principal structure.
(Petition No. 2009-079, § 12.106(2)(a), 1/19/10)
(d) Heating, ventilation, or air conditioning equipment are considered to be part of a structure and shall not be located in any setback, sight distance triangle, or required buffer or screening. Heating, ventilation, or air conditioning equipment may encroach into the required side yard or rear yard by no more than 50 percent of the required yard.
(Petition No. 2010-078, § 12.106(2), (d), 2/21/11)
(5) In respect to a principal structure, architectural features such as cornices, eaves, steps, gutters, and fire escapes may project up to three feet into any required yard, unless they would obstruct driveways, which might be used for service and emergency vehicles. This does not apply to accessory structures.