Spiral shaped staircases are a part of modern homes as it saves space and is less expensive. According to vastu shastra, if spiral steps are built, some of the steps should face either south or west and the rest of the steps can be curved. Never construct any kind of steps, either straight or spiral in the northeastern room or corner. Also we should not build stairs in the south western corner inside the house. In houses that face the west, spiral stairs can be built in the south western side.
One can enter the terrace through the balcony through the west or north west side. In houses that face south, outside stairs can be made through the western side and we can enter upstairs through the balcony on the south. In houses that face east, spirals can be made in the south eastern corner, by following vastu shastra. This helps to ascend facing the west and and enter through the south. For houses that face north, spiraled stairs can be made in the north western corner, so that one can reach upstairs through the west or through the balcony in the north eastern side.