<p> Staircase elevation details The minimum riser height for an egress staircase is<strong> 4 inches and can go up to 7 inches, and the tread depth is 11 inches, while the maximum size between landing should have a height of 12 feet</strong>. Spiral Staircase Dimensions Spiral stairs are a type of staircase that is helical in shape. The treads of the stairs are attached to a central pole. A high ceiling room or a staircase with more than 16 risers will require a staircase that is 12 feet high with a special landing. Its drawback is that it requires a larger space .for more details of <strong>Staircase elevation for more details </strong>download this file.</p>