According to Archibald Sayce, the primitive pictograms of the early Sumerian (i.e. Uruk) era suggest that "Stone was scarce, but was already cut into blocks and seals. <answer>Brick</answer> was the ordinary building material, and with it cities, forts, temples and houses were constructed. The city was provided with towers and stood on an artificial platform; the house also had a tower-like appearance. It was provided with a door which turned on a hinge, and could be opened with a sort of key; the city gate was on a larger scale, and seems to have been double. The foundation stones — or rather bricks — of a house were consecrated by certain objects that were deposited under them."
What was the ordinary building material of Sumerians?
Brick