To unify a façade of two or more storeys, run a single order of pilasters or columns through all of them, from the base to the main cornice.
Rules · Façades · Columns · Pediments
The three purposes of a portico
Give a portico three jobs: to shelter those who arrive, to mark the main entrance, and to give the building dignity and character with its depth of light and shade; proportion it, as a rule, like a temple front.
Stratton distinguishes the portico that expresses the whole mass of a building, the portico as a sub-motive, and several small porticoes used as minor features. It may be attached, with its steps as the chief interest of the façade, or detached as a gateway or screen, as at the Portico of Octavia in Rome.
He directs attention to how porticoes are attached and to the recessing of the wall behind them, with or without vaulted ceilings, and notes the curved portico derived from the round temple.
Related rules
Raise the central nave above the lean-to roofs of the aisles and pierce the upper walls with a row of windows, the clerestory, so that the middle of a wide hall is lit from high on both sides.
nave height ≈ 1½–2 × nave width; one window over each bay of the arcade
Make the corner columns thicker than the rest by a fiftieth of their diameter, because, seen against the open sky, they look thinner than they are.
D corner = D × (1 + 1⁄50); Parthenon: 1.95 m against 1.905 m
Take the plan, the orders and the details from the builders’ pattern books, simplified for timber and for the carpenter: a symmetrical front, a central hall and stair with rooms either side, a doorway under a pediment or fanlight, and mouldings drawn to be made with the plane.
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.
Cite this page Chris Paton, “The three purposes of a portico”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/stratton-portico-purposes. Text, drawings and models licensed under CC BY-NC 4.0.