This architectural drawing is Top view of stair in detail AutoCAD drawing, dwg file, CAD file. The riser is the stair's vertical surface. On the other hand, the tread is the stair's horizontal surface, the area you step on. The part of the tread that drapes over the front of the riser is called the nose. stairs are typically 36 inches wide, which is the least allowed by most building codes. Although not all 36 inches are used, there is still enough room to allow for railings, which can take up a few inches. For more details and information download the drawing file.
