This project was designed to access a loft landing where there was not enough room for a normal horizontal run of stairs. The clients entertained the idea of a ladder but figured access coming down would be more difficult. A spiral stair would have worked but was considered too common and an over-used solution.
Thomas Jefferson developed the idea of alternating treads with a full depth tread on one side and no tread on the other which would allow your traveling foot to reach the next tread without running into the tread your standing on. This allowed the forward edge of each tread to be much closer to each other (5-6" vs. the typical 11" tread depth)
No mechanical fasteners were used to construct the stair except for two large bolts to secure it to the landing above and several small fasteners to attach the handrail.
This solution allowed the clients, their children and guests to ascend the stairs quite normally and descend the stairs facing forward even with a glass in one hand and the other on the handrail.