When Poliochni was first established in the Final Neolithic, it occupied a limited area. During the Blue Period, however, the settlement increased both in size and population, a strong fortification wall was built along the mainland side, and city planning became increasingly organized. Each of the settlement's construction phases is labelled by a colour.
During the Black Period (3700 - 3200 BC) a small settlement of oval huts made of wood and straw on a stone base developed at the centre of the hill. The settlement of the Blue Period (3200 - 2700 BC) was larger and fortified. Apsidal and, later, oblong buildings replaced the huts. The town's main gate, on the southwest, was used until the Yellow Period. It led to two contemporary public buildings, of which one, the so-called Bouleuterion, had stairs on the west and east sides, which indicate that it was probably intended as a meeting place for the elders of Poliochni. This building measures more than 50 square metres and could have accommodated more than 50 people. The second building, to the north, was attached to the south face of the city walls. It has been identified as a public granary with a storing capacity of approximately 260 cubic metres.
The settlement's population increased during the Green Period (2700-2400 BC), and, as a result, the city expanded towards the north side of the hill, where a new retaining wall was constructed. The city wall was extended towards the west, the early enceinte was remodelled, and a new porch was built at the main gate. Finally, a new road network with squares and public wells was created.
The settlement shrank during the Red Period (2400-2200 BC), occupying only the north part of the central hill. It was during this period, however, that the first megarons appeared. Among these monumental rectangular houses, Megaron 832 is a possible ?palace?. The building is 10.10 metres long and 7.90 metres wide, with a central pillar and benches along the walls, and at least three construction phases. Megaron 317, probably a public building, is very similar.
During the Yellow Period, the settlement occupied an area of approximately 20,000 square metres - that is, 10,000 square metres less than during its floruit. This period's road network, the best preserved of all, consisted of a main road that crossed the settlement in a north-south direction and of several tortuous roads that led to different parts of the settlement. Megaron 605, the town's most important building and possible residence of a monarch, is a complex building with storerooms, which dominated the town's central paved square. Nearby, Room 643 yielded a golden hoard, contemporary with the one discovered by Schliemann at Troy, which demonstrates the owner's financial and political importance. The settlement was irreparably damaged by the earthquake of 2100 BC.
There are few architectural remains and no evidence for the existence of an organised settlement for the Brown and Purple Periods (2100 - 1200 BC). The settlement of this last phase is very small and lacks the monumental character of past periods.