Door kits and related methods

A door unit in kit form, comprising:

• a partially preassembled split doorjamb assembly comprising first and second side bases substantially parallel to one another, a header base substantially perpendicular to and interconnecting the first and second side bases, and extensions;
• a door arranged within a space defined by the first and second side bases and the header base of the partially preassembled split doorjamb assembly so that the door, the first and second side bases, and the header base collectively establish a cavity, the first and second side bases and the header base having outer surfaces facing away from the door;
• and
• the extensions comprising first and second side extensions and a header extension that are connectable lengthwise to the first and second side bases and the header base, respectively, and stowed adjacent to and removably secured against the outer surfaces of the first and second bases and the header base opposite to the door, respectively.

A door unit in kit form, comprising:

• a partially preassembled split doorjamb assembly comprising first and second side bases substantially parallel to one another, a header base substantially perpendicular to and interconnecting the first and second side bases, and extensions comprising first and second side extensions and a header extension,
• a door arranged within a space defined by the first and second side bases and the header base of the partially preassembled split doorjamb assembly so that the door, the first and second side bases, and the header base collectively establish a cavity;
• and
• hinges pivotally connecting the first and second side extensions and the header extension to the first and second side bases and the header base, respectively.