Door jamb and sill assemblies are provided. In one aspect, a door jamb weatherstripping assembly includes a weatherstrip member and a retaining member. The retaining member is elongated and is affixed along a length of the door jamb. The retaining member defines a retaining channel for retaining an anchor portion of the weatherstrip member, and a door seal being configured to sealingly contact the face of the door parallely to a weatherstrip portion of the weatherstrip member when the door is closed. According to another aspect, an elongated cap may be secured to the retaining member in a spaced-apart arrangement to jointly form a shielding chamber along an outer portion of the jamb. In another aspect, a door sill assembly having a U-shaped body engaging the bottom edge of the door is provided. The door sill assembly may include side channel seals and bottom channel seals.