Orientation of churches

The orientation of a building refers to the direction in which it is constructed and laid out, taking account of its planned purpose and ease of use for its occupants, its relation to the path of the sun and other aspects of its environment. In church architecture, orientation is an arrangement by which the point of main interest in the interior is towards the east (Latin: oriens). The east end is where the altar is placed, often within an apse. The façade and main entrance are accordingly at the west end.

The opposite arrangement, in which the church is entered from the east and the sanctuary is at the other end, is called occidentation.

Most churches built since the eighth century are oriented. In the many churches where the altar end is not actually the east end of the structure, terms such as "east end", "west door", "north aisle" are commonly used as if the church were oriented, treating the altar end as the liturgical east.

Many early Christians faced east when praying. Due to this established custom, Tertullian says some non-Christians thought they worshipped the sun. Origen says: "The fact that ... of all the quarters of the heavens, the east is the only direction we turn to when we pour out prayer, the reasons for this, I think, are not easily discovered by anyone." Later on, various Church Fathers advanced mystical reasons for the custom. One such explanation is that Christ's Second Coming was expected to be from the east, substantiated using the verse from the Gospel of Matthew: "For as the lightning comes from the east and shines as far as the west, so will be the coming of the Son of Man" (Matthew 24:27).

At first, the orientation of the building in which Christians met was unimportant, but after the legalization of the religion by the Roman Empire in the fourth century, customs developed in this regard. These differed in Eastern and Western Christianity.

The Apostolic Constitutions, a work of Eastern Christianity written between AD 375 and 380, gave it as a rule that churches should have the sanctuary (with apse and sacristies) at the east end, to enable Christians to pray eastward in church as in private or in small groups. In the middle of the sanctuary was the altar, behind which was the bishop's throne, flanked by the seats of the presbyters, while the laity were on the opposite side. However, even in the East there were churches (for example, in Tyre, Lebanon) that had the entrance at the east end, and the sanctuary at the west end. During the readings all looked towards the readers, the bishop and presbyters looking westward, the people eastward. The Apostolic Constitutions, like the other documents that speak of the custom of praying towards the east, do not indicate on which side of the altar the bishop stood for "the sacrifice".

The earliest Christian churches in Rome were all built with the entrance on the opposite side: to the east, like the Jewish temple in Jerusalem. Only in the 8th or 9th century did Rome accept the orientation that had become obligatory in the Byzantine Empire and was also generally adopted in the Frankish Empire and elsewhere in western and northern Europe. The original Constantinian Church of the Holy Sepulchre in Jerusalem also had the altar in the west end.

The old Roman custom of having the altar at the west end and the entrance at the east was sometimes followed as late as the 11th century even in areas under Frankish rule, as seen in Petershausen (Constance), Bamberg Cathedral, Augsburg Cathedral, Regensburg Cathedral, and Hildesheim Cathedral (all in present-day Germany).