Size-Adjustable Pet Door

A method for installing a pet door, comprising:

• cutting a through-opening through a barrier;
• providing a size-adjustable pet door, comprising:
• a first frame unit and a second frame unit, wherein each frame unit comprises slidably mating components that permit each frame unit to have (i) an adjustable height, (ii) an adjustable width, or (iii) both;
• and
• a first flap unit having cutting guides;
• connecting the slidably mating components of each frame unit to form a first opening within each of the frame units that generally aligns with the through-opening within the barrier;
• cutting the first flap unit along one or more of the cutting guides to generally cover the first opening;
• connecting the first flap unit to the first frame unit;
• placing the first frame unit along a first surface of the barrier;
• placing the second frame unit along a second opposing surface of the barrier;
• and
• using a mechanical fastener, securing the first frame unit to the second frame unit in fixed relation to the barrier, thereby forming a passageway for an animal.

A size-adjustable pet door adapted to be mounted to a structural barrier having a through-opening, comprising:

• a first frame unit having a first pair of length-adjustable vertical bar members and a first pair of length-adjustable horizontal bar members which define a first frame unit opening;
• a second frame unit having a second pair of length-adjustable vertical bar members and a second pair of length-adjustable horizontal bar members which define a second frame unit opening;
• a fastener coupling the first frame unit and the second frame unit to the structural barrier, and
• a flap unit coupled to one of the first and second frame units, the flap unit having a series of vertical cutting guides and one or more horizontal cutting guides,
• whereby the first and second frame units may each be varied in size by adjusting the length of the length-adjustable vertical bar members and the length-adjustable horizontal bar members to conform with the size of the barrier through-opening, and the size of the flap may be adjusted for the size of the opening formed by the first and second frame units by removing portions of the flap through cutting along the series of vertical cutting guides and/or the one or more horizontal cutting guides.