Stair riser

A stair riser is the vertical face between one tread and the next. Riser height is the vertical distance between the walking surfaces of two consecutive steps. Together with tread depth, this one dimension decides whether a stair feels steep or easy.

Why riser height matters

After a few steps, people settle into a rhythm set by the riser height and stop looking at their feet. That is why every riser in a flight must be identical; a single step that is higher or lower than the rest is enough to cause a trip or a fall. The most common mistake is a difference at the first or last step, usually because the stair was built to structural levels without allowing for the thickness of floor finishes. The floor-to-floor height is divided by the number of risers to get an equal riser size, and tread depth is then chosen using the comfort rule. Maximum riser heights for homes, schools and public buildings are set out in regulations. Some stairs leave risers open; this looks light but needs separate thought where small children are concerned.

Risers in the image

Risers are the lines that give a stair its rhythm. In a render, a slight tonal difference between riser and tread, or a thin shadow under each nosing, makes a stair easy to read and convincing.