What is a portico?

A portico is a roofed space whose open side is carried by a row of columns or piers. In most cases it is the colonnade standing in front of a building’s facade as its entrance, with an entablature above and often a triangular pediment.

The portico is the signature of the classical temple, and therefore of every architecture that claims descent from it: Renaissance, Palladianism, neoclassicism and Greek Revival. Think of town halls, museums, exchanges and villas with a columned porch raised on a flight of steps.

Components

• Columns in one of the classical orders — Doric, Ionic, Corinthian, Tuscan or Composite
• Architrave, frieze and cornice, together the entablature
• Pediment, the triangular gable above the cornice, with the tympanum as its field
• Steps and platform, on which the portico usually stands
• Pronaos, the roofed space between the colonnade and the actual entrance of a temple

Naming by column count

Classical architecture names a portico after the number of columns in its front row: tetrastyle (four), hexastyle (six), octastyle (eight), decastyle (ten). A colonnade that runs all the way round the building is a peristyle.

Portico, portal and portiek

All three share the same Latin root (porta, gate) and are frequently muddled:

• Portico — a colonnade, a term from classical architecture
• Portal — the designed entrance with its surround; in structural engineering a rigid frame
• Portiek — Dutch for the recessed, street-facing covered entrance area of a building

Points to watch in restoration

1. Columns really do carry. In a portico the colonnade is almost always structural. Replacing or moving one is structural work, not decoration.
2. Water is the enemy. Horizontal cornices catch rain. Check the flashings and the drainage; most stone decay starts here.
3. The wrong material accelerates decay. Repair stone and render with a mortar that is softer and more vapour open than the substrate. Cement-based repairs on soft limestone cause the surrounding stone to spall.
4. Columns are rarely straight. Classical columns have entasis, a slight swelling. Always take the original profile off the building before reproducing anything.

Related terms

• Column
• Pediment
• Entablature
• Pronaos
• Portal
• Natural stone

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