Etruscan towns were mapped out, first tracing with a plough two main perpendicular axes, called the cardo (north-south) and decumanus (east-west), then dividing the four areas thus obtained into insulae using roads running parallel to the cardo and decumanus. This precise city planning is still to be seen today in some towns of ancient Etruria, though it is not unique to Etruria - the idea of a town based on two perpendicular roads was commonly used in Greece and was taken up again in later periods by Rome for its military camps and town (for example, Augusta Praetoria and Augusta Taurinorum, the present-day Aosta and Turin).
The towns were enclosed by thick walls, which (with graves and temples) provide the only evidence for Etruscan stone architecture. Other materials used were clay, tuff and limestone; marble was all but unknown. Towns were entered through gates, of which there were usually seven or four (though some towns had five), with the main ones being at the ends of the decumanus and cardo. At first they were simple lintels, but from the 5th century BC they began to assume the form of artists, built with dry-stone joints between enormous blocks of tuff. Late Etruscan gates, such as the arch of Volterra, were further decorated with friezes and bas-reliefs on their main sections (the keystone and the upper levels). With the growth of Rome's military power, the Etruscan town was progressively assimililated into the Roman world and mentality. In a disadvantageous position (economically, socially, militarily and politically), Etruscan towns were reduced from the beating heart of Mediterranean commerce itself to merely settlement centres directed by an Etrusco-Roman elite which brought an end to an independent Etruscan architectural and artistic tradition.
Etruscan architectural features are too extensive at Rome to be considered a mere influence. The oldest wall at Rome, dating to the early monarchy, is built in the style called opus quadratum after the roughly 4-sided blocks. The style was in use at Sutri, Falerii, Ardea, and Tarquinia.
In addition to their walls, the Etruscans insisted on sewage and drainage systems, which are extensive in all Etruscan cities. The cloaca maxima, “great sewer”, at Rome is Etruscan. The initial Roman roads, dikes, diversion channels and drainage ditches were Etruscan. More importantly, the Etruscans brought the arch to Rome, both barreled arches and corbelled arches, which can be seen in gates, bridges, depictions of temple fronts, and vaulted passages.
Homes also were built in Etruscan style: a quadrangle of rooms around an open courtyard. The roof was of a type called cavoedium tuscanicum: two parallel beams crossing in one direction on which rafters were hung at right angles.
Etruscan graves have survived since they were made of stone. In Etruscan religion man, weak and insignificant in life, ' required a cosy and familiar environment in which to spend the afterlife, with personal objects from life. This explains the care with which necropoleis were built and the fact that Etruscan painting is almost exclusively found in a funerary context. The walls of necropoleis were painted in lively colors (imitating, in some cases, the vault of the sky, or scenes of everyday life) to contrast against the darkness, symbol of spiritual death. The necropoleis were generally placed outside a town's city wall, but oriented parallel to the cardo or decumanus street. Therefore Etruscan necropoleis are a very significant source, historiographically speaking, as they allow us to see Etruscans' daily life, beliefs and habits, which we could not get exclusively from the written texts. Etruscan tombs and catacombs are classified into three types: