Eastern Orthodox church architecture

The narthex is the connection between the church and the outside world and for this reason catechumens (pre-baptized Orthodox) and non-Orthodox are to stand here (note: the tradition of allowing only confirmed Orthodox into the nave of the church has for the most part fallen into disuse). In monastic churches, it is usual for the lay people visiting the monastery to stand in the narthex while the monks or nuns stand in the nave. Separating the narthex from the nave are the Royal Doors (either because Christ passes through them in the liturgy, or from the time of the Byzantine Empire, when the emperor would enter the main body of Hagia Sophia, the Church of Holy Wisdom, through these doors and proceed up to the altar to partake of the Eucharist). On either side of this portal are large brass candlestands called menalia which represent the pillars of fire which went before the Hebrews into the promised land.

A view of the nave in the Russian Orthodox Cathedral of the Holy Trinity in Chicago (designed by Louis Sullivan)

The nave is the main body of the church where the people stand during the services.[4] In most traditional Eastern Orthodox churches there are no seats or pews as in the West, but rather stacidia (A high-armed chair with arm rests high enough to be used for support while standing); these are usually found along the walls. Traditionally there is no sitting during services with the only exceptions being during the reading of the Psalms, and the priest's sermon. The people stand before God. However, many exceptions to this can be found in Western countries, especially the United States, where familiarity with Catholic and Protestant churches has led to similarities in church furnishings. It is not uncommon to encounter both pews and kneelers.

In some more traditional churches, mostly in Greece, a special chandelier known as a polyeleos can be found. This chandelier is usually adorned with candles and icons and is pushed to swing during its respective service.

The walls are normally covered from floor to ceiling with icons or wall paintings of saints, their lives, and stories from the Bible. Because the church building is a direct extension of its Jewish roots where men and women stand separately, the Orthodox church continues this practice, with men standing on the right and women on the left. With this arrangement it is emphasized that we are all equal before God (equal distance from the altar), and that the man is not superior to the woman. In many modern churches this traditional practice has been altered and families stand together.

Above the nave in the dome of the church is the icon of Christ the Almighty (Παντοκρατωρ/Pantokrator, "Ruler of All"). Directly hanging below the dome (In more traditional churches) is usually a kind of circular chandelier with depictions of the saints and apostles, called the horos, which is the same as the polyeleos mentioned above.

The nave of an Orthodox church can vary in shape/size and layout according to the various traditions within the Church. The two most common layouts inside Orthodox churches since Justinian have been a cruciform layout, an open square/rectangular layout, or a more linear layout with side-aisles. However, the latter of which has fallen out of use since the Great Schism, as it was more widely used in Western churches and better suited the services celebrated in them than in Eastern Rite churches. The two former layouts, the open square (or rarely, circular) and the cruciform have been found best suited to celebration of the Divine Liturgy. These two interior layouts tend to be square/circular in form rather than elongated.

The cruciform is the oldest of the two interior layouts and seems to be of Byzantine origin. It comes from the adaptation of two of the earliest Christian architectural forms, the basilica and the octagonal/circular form. The cruciform church often includes side-aisles similar to the Western basilica, but they are often very short and cut open in the middle, leaving a large cross shape through the middle of the church. The open square/circle is the newer of the two forms. It is most commonly found in Eastern European churches and more modern Greek churches. This church retains the earlier square/circular shape; however, the side-aisles have been removed, thus opening the space completely. This has found wider use across the world in more recent years with the invention of steel, as it allows for the dome to be supported without the need for massive arches and columns which were main features of the older cruciform churches.

A depiction of the front of an iconostasis from Stepan Shukhvostov's Church of St. Alexis in the Chudov Monastery of the Moscow Kremlin

The iconostasis, also called the τεμπλον/templon, it is a screen or wall between the nave and the sanctuary, which is covered with icons. There will normally be three doors, one in the middle and one on either side. The central one is traditionally called the Beautiful Gate and is only used by the clergy. There are times when this gate is closed during the service and a curtain is drawn. The doors on either side are called the Deacons' Doors or Angel Doors as they often have depicted on them the Archangels Michael and Gabriel. These doors are used by deacons and servers to enter the sanctuary.

Mid-17th-century iconostasis at Ipatiev Monastery. To either side of the Holy Doors are Christ Pantokrator and the Theotokos; above them, the Great Feasts; above them, the Deesis; above that Prophets to either side of Our Lady of the Sign; above them the Apostles to either side of the Holy Trinity.

Typically, to the right of the Beautiful Gate (as viewed from the nave) is the icon of Christ, then the icon of St. John the Baptist; to the left the icon of the Theotokos, always shown holding Christ; and then the icon of the saint to whom the church is dedicated (i.e., the patron). There are often other icons on the iconostasis, but these vary from church to church. The curtain is also drawn and opened at various points in the service.

The area behind the iconostasis reached through the Beautiful Gates or Angel Doors is the sanctuary or altar. Within this area is the altar table, which is more often called the holy table or throne; the apse containing the high place at the center back with a throne for the bishop and the synthronos, or seats for the priests, on either side; the Chapel of Prothesis on the north side where the offerings are prepared in the Proskomedia before being brought to the altar table and the holy vessels are stored; and the Diaconicon on the south side where the vestments are stored.

Orthodox Altars are usually square. Traditionally they have a heavy brocade outer covering that reaches all the way to the floor. Occasionally they have canopies over them. All Eastern Orthodox altars have a saint's relics embedded inside them, usually that of a martyr, placed at the time they are consecrated. Atop the altar table at the center toward the back is an ornate container usually called the tabernacle where the reserved Eucharistic elements are stored for communion of the sick. It is often shaped like a model of a church building. In front of this is placed the Gospel book, which usually has a decorated metal cover. Under the gospel is a folded piece of cloth called the eiliton. Folded within the eiliton is the antimension, which is a silken cloth imprinted with a depiction of the burial of Christ and with relics sewn into it. Both these cloths are unfolded before the offerings are placed on the altar table. Behind the altar is a seven-branched candlestick, which recalls the seven-branched candlestick of the Old Testament Tabernacle and Temple in Jerusalem. Behind this is a golden processional cross. On either side of the cross are liturgical fans (Greek: ripidia or hexapteryga) which represent the six-winged Seraphim. Against the wall behind the altar is a large cross. Hanging from the cross is usually a flat iconographic depiction of Christ (corpus) which can be removed during the 50 days following Pascha (Easter).

Traditionally, no animal products other than wool and beeswax are allowed in the sanctuary/altar. In theory, this prohibition covers leather (in the form of leather-bound service-books and shoes), but this is not always enforced today. Money is also forbidden. None may enter the altar without a blessing from the priest or bishop, and personal jewelry, such as rings and earrings, is not worn by those serving there.