Monumental Sumerian architecture
Tripartite Plan (Ubaid, Uruk, Jemdet Nasr)
Present in the Ubaid and Uruk eras, the tripartite plan of Sumerian temples consists of a rectangular central hall flanked by subsidiary rooms. At one of the short walls is the altar, and this wall is usually elaborately decorated with recesses. The entire interior is carefully plastered. A hearth or offering place in the center of the hall is also standard.
The entrance is usually at one of the long walls; since those entering must turn to approach the focal point (the altar) the triparte temple has a so-called bent axis. Exterior walls are usually niched-and-buttressed, sometimes with cone mosaic as well, and the corners are oriented to the points of the compass. The whole complex is often atop a platform.
T-Shaped Plan (Ubaid, Uruk, Jemdet Nasr)
Arising in temples of the Uruk era, the T-shaped plan is much like the tripartite plan except that the central rectangular hallway is T-shaped, sometimes with additional rooms along the head of the T. This plan is well attested in Ubaid houses before it came into use for temple architecture; this gives continuity, and the use of house plans for temples reflects the Sumerian notion that temples were houses/dwellings for the gods.
Mesopotamian Megaron / Headmen's Houses (Uruk)
In the north of Mesopotamia at Tepe Gawra are great examples of the megaron -- basically tripartite, as in the south, with a large central room with an elaborate hearth, flanked on either side by smaller rooms. However, the side rooms are longer than the central hall at one end, thus forming a sort of porch.
The plan itself, and the associated pottery, seems to have Anatolian connections. While originally identified as temples due to their size and the number of associated infant and other burials, they perhaps represent élite houses.
Monumental Architecture of the Early Dynastic Era
Much of our knowledge of Early Dynastic temple architecture comes from shrines situated in the middle of domestic quarters -- in the words of Crawford 1991 (p 65), these are "parish churches rather than major cathedrals." Also, much of our Early Dynastic evidence is from the peripheral, and perhaps provincial, Diyala region (in Ur, only subsidiary service temples have been excavated). Thus, the lack of any standardized temple plan found in the Early Dynastic era is as likely due to the political fragmentation of the time (and looking inwards to idiosyncratic local tastes), as it is due to the possibility that standard temple plans exist but remain in unexcavated urban centers.
An Early Dynastic trend is the temple as a self-contained unit within a perimeter wall. The Sin Temple (Khafaje) typifies this: it began as a typical Jemdet Nasr tripartite temple; but in the Early Dynastic I it expanded into an amplified version of contemporary domestic architecture, with several rooms around a central courtyard. It had its own ovens, storage, personal quarters and other domesticities. This is also typified by the Square Temple (Tell Asmar) and the Ishtar Temple (Mari), and reflects the shift from a tributary to an oikos economy. Another trend is the presence of multiple shrines (rather than just one) in the same temple, each accompanied by many so-called constantly adoring statues left by the pious.
Temple Ovals (Early Dynastic)
Temple ovals arose in the Early Dynastic era and are typified at Tutub (modern Khafajah) and Tell al-Ubaid. They consisted of a big circular enclosure wall built upon virgin sand; at Tutub, some 64,000 m3 were removed and replaced with the same amount of sand, thus ritually preparing the ground and covering up the prior structure. Within the enclosure wall was a priest's house, an interior courtyard and a temple on a raised platform.
Later temple-builders did not even demand virgin sand, and such an undertaking suggests a robust economy. This reflects the role of the temple oval at the heart of the economy as the node that dominated the landscape and exacted tribute, and also connected rural primary producers and urban specialists to exchange products. Its position necessitated monumental architecture, which was a facet of its dominance and was inseperable from its divine nature.
There is no clear example of house-plan temples for the Agade era, but this is likely due to limited excavation rather than a genuine absence, which would break continuity with the house-plan temples sporadic in the Early Dynastic era and predominant and standardized in the Ur III era. Only the North Temple (Nippur) reliably dates to this era, based on mudbricks stamped with the names of Sargon and Naram-Sin, but it only likely is in the house-plan category.
Of the Diyala sites, only Khafaje's Abu Temple is firmly dated to the Agade era. It was a single-roomed (later subdivided in two) bent-axis shrine with a service room complete with an oven. Khafaje's Nintu and Oval temples at latest survived into the early Agade era. From the north are two more shrines: one at Nuzi, approached by a courtyard, and later with a service room or second shrine; and on the Tell Taya citadel, distinguished by small stores on either side of the altar.
Ur III Era
It is perhaps facile to equate the return of a unified political rule under the kings of the Third Ur dynasty with the return to a standard temple plan, but it is an attractive parallel to draw. This new orthodoxy certainly contrasts sharply with the architectural and political diversity of the Early Dynastic period. The advent of the deified rulers of Ur III brought church and state together into one integrated system, administered from one centre and controlling all the Sumerian plain. This same move towards standardisation can be seen in other areas too, in the introduction of a single system of weights and measures, in the development of a standardised script and grammar and even perhaps in the formal and repetitive designs of the cylinder seals of the period. Crawford 1991, p 71
Ziggurats likely arose in the late Early Dynastic era, but it was not until Ur III king Ur-Nammu's construction campaigns that they were erected throughout Sumer. They consisted of tall platforms, one above the other, with likely a shrine atop it all. Click for details on the ziggurats of Mesopotamia.
Ziggurats continued throughout Mesopotamian history, and parallels have been drawn to the ziggurats of the Americas. However, such similarities are simply due to the exigencies of primitive (and sometimes contemporary!) architecture, particularly a desire to reach toward the heavens.
Clay Cone Decoration
The use of cone mosaics to produce technicolor designs, particularly on the exterior of buildings. First attested during the Ubaid period.