For the first time, the International Fire Code (IFC) contains references to PV systems. The 2012 edition addresses firefighter and emergency personnel access to rooftop PV systems on commercial buildings and residences. Roof access is needed during firefighting so that holes can be made to get smoke out of a building.
Residential rooftops are divided into two categories—hip roofs and ridge roofs. Hip roofs require a 3-foot-wide access path from the eave to the ridge on the face of the roof on which PV modules are mounted. Ridge roofs require 3-foot-wide access paths between the eave and the ridge on both sides of the array, since, unlike a hip roof, there is not an adjoining roof section that can easily be accessed. These access pathways must be over structural building elements, and may not be located on top of an overhang. Additionally, modules cannot be located any closer than 3 feet from the roof’s ridge, regardless of the roof geometry.
Modules placed on both sides of a valley or hip must be at least 18 inches from the center of the hip or valley. If only one side of a hip or valley has modules on it, then the modules can extend all the way to the corner of the hip or valley, provided that the adjacent surface is as long as the roof surface to which the modules are mounted.
These requirements do not apply to roofs with a pitch of 2:12 (≈ 9.5º) or less, nor do they apply to detached, uninhabitable structures, such as carports or shade structures. With permission of the local fire official, these requirements can be waived so long as it is determined that the array’s position will not interfere with local methods for emergency ventilation.
Check with your local jurisdiction regarding adoption of the 2012 IFC. Some jurisdictions may be enforcing these standards, or some variation of them, even if they have not yet officially adopted the 2012 IFC.