Colonnades in Architecture

A long row of evenly spaced columns supporting a roof or a horizontal beam, running along the front or side of a building or framing an open walkway, is a colonnade. It is one of the most enduring devices in architecture — at once a structural system, a shaded route to walk, and a powerful visual rhythm. From the temples of ancient Greece to the curving sweep of St Peter’s Square, the colonnade has shaped how buildings meet the public realm for more than two and a half thousand years.

This article explains what a colonnade is, how it works structurally, where the idea came from, the main types you will encounter, and why architects still use the colonnade today — including in hot climates, where its shaded walkways are as practical as they are dignified.

What a colonnade is

A colonnade is a series of columns set at regular intervals, carrying an entablature (a horizontal band of beam, frieze and cornice) or a run of arches above them. The defining quality is the row: a single column is just a support, but a line of them, equally spaced, creates a rhythm and a covered or framed space alongside the building.

The colonnade can stand free, as a covered walkway, or be attached to a building as a porch or a screen along its face. When a colonnade wraps around a courtyard or temple on all sides it forms a peristyle; when it projects forward to shelter an entrance it becomes a portico. The spacing between columns is called the intercolumniation, and in classical architecture it was governed by careful proportional rules.

How a colonnade works structurally

Structurally, a colonnade is the simplest kind of frame: vertical columns carry vertical loads down to the ground, and a horizontal beam or entablature spans between them to carry the roof above. Each column works in compression — it is being squeezed by the weight bearing down — which is exactly what stone, the original colonnade material, does well. Stone is strong in compression and weak in tension, so the classical colonnade kept its members short and stocky and the spans between columns modest.

This is why classical colonnades have columns set fairly close together. A horizontal stone beam, or architrave, spanning between two columns is in bending, and stone is poor at resisting bending; span it too far and it cracks at the bottom. Keeping the gap small kept the stone beam safe. When builders later wanted wider openings, they replaced the flat beam with an arch springing between columns — an arcade rather than a colonnade — because the arch carries load in compression around its curve and can span much further. The distinction matters: a colonnade carries a straight entablature; an arcade carries arches.

Understanding compression and the limits of the material is the same reasoning a structural engineer applies today, whether the columns are stone, masonry or — as is now common — reinforced concrete or steel. The behaviour of reinforced concrete columns lets modern colonnades use slimmer supports and wider spacing than stone ever allowed.

Greek and Roman origins

The colonnade reached its first great refinement in ancient Greece. The Greek temple was, in essence, a building wrapped in colonnades — rows of columns surrounding the inner chamber, carrying the entablature and roof. The Greeks developed the three classical orders — Doric, Ionic and Corinthian — each defining the proportion, profile and ornament of the column and the entablature it carried. The Parthenon in Athens is the canonical example: its surrounding colonnade is a masterclass in proportion and subtle optical refinement.

The Romans inherited the colonnade and used it lavishly — along streets, around forums and markets, and as covered shopping arcades. They also combined columns with arches and vaults, expanding what the system could do. Long colonnaded streets gave Roman cities shaded, ordered public routes, a function the colonnade still performs.

Types of colonnade

Architects classify colonnades in a few useful ways:

By position: a free-standing colonnade forms a covered walkway; an engaged colonnade runs along a building’s face; a peristyle surrounds a court or temple.
By column spacing: classical theory named the rhythms — from closely spaced (pycnostyle) to widely spaced (araeostyle) — each suited to a different order and effect.
By number of columns across a front: tetrastyle (four), hexastyle (six), octastyle (eight) and so on, describing temple and portico fronts.

One of the most famous of all is Bernini’s vast curving colonnade enclosing St Peter’s Square in Rome — four rows deep, sweeping out like welcoming arms to embrace the gathered crowd. It shows the colonnade working at urban scale, as much a shaper of public space as a part of a building.

The colonnade in tropical and modern architecture

Beyond the classical, the colonnade has an intensely practical role in hot, wet climates: the shaded, sheltered walkway. The covered “five-foot way” along the front of Singapore and Malaysian shophouses is a colonnade in spirit — a continuous arcaded or columned walkway that shelters pedestrians from sun and tropical rain while linking shopfronts. It is a climate-responsive use of the same ancient idea, and a defining feature of the regional streetscape.

Modern architects continue to use colonnades to mediate between inside and outside, to give a building a dignified public face, and to create comfortable transitional space. With steel and reinforced concrete the columns can be slimmer and more widely spaced, but the underlying logic — a rhythm of supports carrying a horizontal above, framing a sheltered route — is unchanged from the Greek temple. If you are designing or restoring a colonnade and need to confirm how the columns and beams carry load, our structural-engineering consultancy can advise.

Frequently asked questions

What is a colonnade?

A colonnade is a row of evenly spaced columns carrying a horizontal entablature or beam above them, used to support a roof, frame a building’s face, or create a covered walkway alongside it.

What is the difference between a colonnade and an arcade?

A colonnade carries a straight horizontal beam or entablature across the tops of its columns, while an arcade carries a series of arches between its supports; the arch lets an arcade span wider openings than a flat-beamed colonnade can.

How does a colonnade carry load?

Each column works in compression, carrying the weight of the roof and beam straight down to the ground, while the horizontal beam between columns spans in bending; stone’s weakness in bending is why classical colonnades keep their columns closely spaced.

What is a peristyle?

A peristyle is a colonnade that runs around all four sides of a space, such as a courtyard or a temple, enclosing it with a continuous covered walkway of columns.

Are colonnades still used today?

Yes; colonnades still give buildings a dignified public face and create shaded, sheltered walkways, and in tropical climates the covered colonnaded walkway in front of shophouses is a practical, climate-responsive version of the same ancient idea.

Designing or restoring a colonnade and need the columns and beams checked for load? Talk to our consultancy or get in touch.