The mainstream of secular architecture in general follows closely on that of the Mauryan period, except in so far as there is an extraordinary change in the quality of domestic architecture in almost all parts of the subcontinent, manifested in the much greater use of burnt brick and tile, and consequently greater permanence of structures.
Not much is known about the architectural patterns in the rural settlements but we know a lot more about them in the cities from both archaeological as well as literary sources.
The cities appear to have been surrounded by protecting walls, pierced by gateways and furnished with lofty watch-towers. The Mahajanaka Jataka refers to the gate, watch tower and the walls of the city of Champa. The city of Girivraja has been described as an impregnable city in the Mahabharata, being surrounded by five hills, namely Vaihara, Varaha, Vrisabha, Risigiri and Chaityaka.
The walls of the city, constructed of cyclopaean masonary can still be seen. The Milinda-panha offers us a graphic picture of the city of Sagala. It was a city “fine and regular, measured out into quarters, with excavated moats and ramparts about it, with stout gate houses and towers, with market places, crossroads, street corners and public squares, with clean and even roads, with regular lines of open shops, well provided with park, gardens, lakes, lotus ponds and wells, adorned with many kinds of temples of gods, free from every faults and standing in all its glory.”
This eloquent description of the city of Sagala appears to hold good for the period 325 BC- AD 300. The archaeological excavations at Shaikhan Dheri (ancient Puskalavati), Sirkap and Sirsukh (two cities at Taxila), Sishupalagarh, Nagarjuni-konda, Satanikota, etc. show similar city planning. A reconstruction, hypothetical but authoritative, may also be made from the relief representations of Bharhut, Sanchi, Amaravati, Mathura etc.
In which many of the historical cities including Rajagriha, Shravasti, Varanasi, Kapilavastu and Kusinagara have been shown, as required by the stories and legends that they represent. These relief compositions show that the houses were constructed of wood and bamboo. Every essential of wooden technique is scrupulously imitated in these reliefs and this strict adherence to a wooden style presumes the existence of an age of wood in the history of Indian architecture.