text: a 17" riser would be like stepping up a flight of stairs made out of piano benches.  7-5/16" is a more standard riser height.  I would guess that you need a quantity of 17 risers, each at a height of 7-5/16".  That gives you a floor to floor distance of 10'4", which is a reasonable distance between two floors of a house/residence/etc.  The question to ask your architect or draftsman is "how deep are the treads?"\n\nMore basically, the riser is the piece of the stair that is vertical, and the tread is the piece of the stair that is horizontal.  Floor-to-floor measurements are often made from finished surface to finished surface of two storeys/stories of a house.  Building codes typically require that continuous runs of stairs all have the same riser height and tread depth, within a tolerance of usually less than 1/2 inch.  without this, we'd all be living in Willy Wonka houses and tripping up and down the stairs all the time.