Fenestration assemblies including composite frame cores and methods for same

A fenestration assembly includes a glazing unit includes a pane spacer between exterior and interior panes proximate glazing unit edges. A fenestration frame is coupled around the glazing unit and includes a frame core extending around the glazing unit. The frame core includes a unitary core wall including a composite material that is hollow and extends continuously from a core interior face to a core exterior face. A metal glazing cap is coupled with the frame core. The metal glazing cap having a cap end indirectly engaged with the glazing unit along the interior pane, and the cap end is remote from the pane spacer. Each of the core exterior face, the pane spacer and the metal glazing cap are thermally isolated from each other with the frame core including the unitary core wall.