Proportion every step so that twice its height plus its depth equals the length of a natural pace on the level: two feet, or 24 pouces.
2 r + g = 24 pouces ≈ 65 cm (modern practice: 60–66 cm)
An odd number of steps
Give the flight of steps before a temple an odd number, so that one who starts with the right foot will also set the right foot first on the top.
Vitruvius also asks that the risers of temple steps be no more than about ten inches nor less than nine, and the treads between a foot and a half and two feet. The rule of the right foot is a piece of augury, but it records something real: a flight is walked as a rhythm, and designers since have counted steps as carefully as they have measured them. Long flights are broken by landings; modern codes typically allow no more than sixteen to eighteen risers in one flight.
Related rules
Hold that the beauty of the orders comes from fixed proportions that please by nature, as consonances do in music; where the ancients differ, the differences answer to circumstances such as distance and height.
Judge every building against the first shelter: four trees for columns, branches laid across them for the entablature, and a pitched roof whose end makes the pediment. These three are the essential parts; all else is added.
Let columns stand free, round and upright, carrying a straight entablature directly; do not engage them in walls, replace them with pilasters, or set them on pedestals.
Avoid the ornaments that have no model in the hut: broken or curved pediments, pediments on the long side of a roof, orders piled storey upon storey on a church front, arches carried on columns, and twisted or cabled shafts.
Seek in every building only fitness (solidity, healthiness, convenience) and economy (symmetry, regularity, simplicity); a building that has these will please, and ornament added for its own sake is waste.
Cite this page Chris Paton, “An odd number of steps”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/odd-number-of-steps. Text, drawings and models licensed under CC BY-NC 4.0.