Structural panels, components and assemblies are described. The structural panel system comprises one or more panels having interlocking profile features providing convenient assembly of multiple panels to provide pre-assembled panels or structures, or components that are easily shipped and assembled at a site to satisfy a variety of building requirements, transport requirements, structural panel requirements, and the like. An integrated raceway gutter system may be provided for evacuation of moisture in conjunction with end-caps having a coordinating structure. Insulation components may be positioned at an interior side of panels and may be separated from the capillary break by a moisture impervious and/or heat reflective layer. Cladding panels may be pre-assembled, along with additional structural building components, to provide pre-assembled structural insulative (and non-insulative) panels. Additional system components, including end caps, a sill, a head, a façade, a jamb and accessory brackets, are also described.