A "u-shaped" stair with only one intermediate landing, as you describe, is just a simple switch-back stair that has a much wider landing, resulting in a greater distance between the two sets of risers than may be normal. This type of stair has the same rectangular shape as a "normal" switchback stair with the exception of a wider landing.

Another version of a "u-shaped" stair might have two landings and three flights of risers, in more nearly square arrangement.

Perhaps someone will post a graphic to help you.

The rectangular landing would be approximately halfway between the floors.

Draw seven 10" deep treads descending from the landing to the lower floor and nine 10" treads ascending from it to the upper floor. These two stair runs would be side by side. How far apart they are is up to you.

It is customary to cut off the first floor stair drawing where the treads are higher than 3 ft from the floor and show the treads above that level dotted. The upper plan would show all of the treads unless some are hidden by the upper floor.

This would be a schematic drawing of the stair risers. To draw what would actually be seen in plan, add a 1" nosing to the leading edge of each tread.

This post was edited by Renovator8 on Mon, May 6, 13 at 16:36