South Carolina Code of Regulations
Chapter 8 - BUILDING CODES COUNCIL
Article 12 - INTERNATIONAL RESIDENTIAL CODE
Section 8-1204 - IRC Figure R302.1 Exterior walls

a. The minimum fire separation distance for improvement constructed on a lot shown on: [i] a recorded bonded or final subdivision plat, or [ii] a sketch plan, site plan, plan of phased development or preliminary plat approved by the local governing authority which was recorded or approved prior to the implementation of IRC 2012 which shows or describes lesser setbacks than the fire separation distances provided in Table R302.1(1) shall be equal to the lesser setbacks, but in no event less than 3 feet.

b. The minimum fire separation distance for improvements constructed on a lot where the local governing authority has prior to the implementation of IRC 2012: [i] accepted exactions or issued conditions, [ii] granted a special exception, [iii] entered into a development agreement, [iv] approved a variance, [v] approved a planned development district, or [vi] otherwise approved a specific development plan which contemplated or provided for setbacks less than the fire separation distances provided in Table R302.1(1) shall be equal to the lesser setback, but in no event less than 3 feet.

Exception 7: Aesthetic roof and siding projections may extend beyond the common wall of a townhouse unit over an adjoining unit's property line as long as the construction of the projection does not damage the integrity of the fire rated assembly, the projection is completely supported by the common wall, the projection is protected by the one-hour construction or fire retardant-treated wood, and the projection is limited to 18-inches. These projections shall not contain any plumbing, electrical, or mechanical installations. An easement may be required by the jurisdiction to ensure future access to this projection for repair and maintenance.