Corner Doors (or “One-legged” doors) are used on homes where one side of the cellar stairwell is also the side of the house and therefore there is no foundation upon which to mount the cellar door frame.
Use the following illustration as a guide to assist you while you take the required measurements listed below.
(You may want to print this page and use it on the jobsite) These doors can be built either way… “right legged” or “left legged”. The side of the new door that will be metal determines its name. (A “left legged” door is shown in the drawing)