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Portico is a term usually used to describe a porch leading to the entrance of a building, its roof supported by columns and with a pedimentedLow-pitched gable above a portico or façade. gable. The variants of porticos are named by the number of their supporting columns: distyle for two; tristyle for three; tetrastyle for four; pentastyle for five; hexastyle for six; heptastyle for seven; octastyle for eight; enneastyle for nine; decastyle for ten; and dodecastyle for twelve.[1][2] An even number of columns is more common, as it allows for a central void, giving easier access to the door.[2]
Portico variants can also be described by the placement of their supporting columns. An engaged portico is one in which the portico, rather than standing in front of the building, is embedded in its front wall. In a prostyle portico the columns are set in a line in front of and detached from the wall of the building behind, and in an in antis portico the columns are set in a line between projecting walls.[2]
The term portico is also used to describe a covered ambulatoryGeneral term for a covered walkway, and more specifically for the walkway linking the two chancel aisles behind the high altar. forming a separate structure.[2]