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.
Rules · Theory · Materials · Walls · Roofs
The four elements
Understand every building as a combination of four elements (the hearth, the roof on its supports, the enclosure and the mound), each descended from a craft: ceramics, carpentry, weaving and masonry.
Semper replaced Laugier’s tree-hut with an anthropology of building. The hearth came first, as the gathering point of the family; the roof, the enclosure and the raised floor protected it. His evidence was ethnographic as well as archaeological, above all a Caribbean hut shown at the Great Exhibition of 1851, with its timber roof frame, its woven mat walls and its raised clay floor. Because the enclosing wall began as a hung textile, Semper argued, its surface is by nature a dressing, and colour and pattern belong to it.
Related rules
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.
A saddle surface in which two opposite corners are raised and two lowered is a hyperbolic paraboloid; it contains two families of straight lines, so it can be formed with straight boards and yet has double curvature.
y = k·x·z (or any bilinear patch through four points not in one plane)
A thin curved shell carries load by the membrane forces in its surface, not by bending; so shape it to its loads and supports, and it can span great distances with a thickness of a few centimetres.
span ÷ thickness of a good shell ≈ 400–1000 (an egg: ≈ 100)
In a framed building the columns and beams carry every load; the outer wall can be reduced to a light cladding hung on the frame, floor by floor, and need grow no thicker as the building rises.
load-bearing wall: thickness grows with height · frame: cladding thickness constant
The outward form of a building should arise from, and express, what the building does and how it is made, as the form of every living thing expresses its life.
Cite this page Chris Paton, “The four elements”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/semper-four-elements. Text, drawings and models licensed under CC BY-NC 4.0.