Order the church as a single path: a colonnaded atrium, a narthex, the long nave drawn toward the altar, and the apse framed by a triumphal arch at the end of the axis.
Keep the public buildings and porticoes clear
Repair the public buildings of the city before beginning new ones; and pull down the booths, sheds and houses that private people build into the public porticoes or against the walls of public buildings.
The title on public works in the Theodosian Code is a record of a losing struggle. Law after law tells governors not to start new buildings for their own glory while the old ones fall down, forbids stripping public buildings for materials, and orders the removal of private structures that have crept into porticoes, onto streets and against granaries, baths and walls, for their fire risk as well as their ugliness.
That the laws had to be repeated shows how the late-antique city was changing. Traders put up booths between the columns of the colonnaded streets; the booths became shops, the shops houses; and over generations the broad Roman avenue narrowed into the winding lane of the medieval and Islamic town. Archaeology shows the same process from Syria to Italy.
Related rules
Lay out a city’s streets so that they do not line up with the directions of the principal winds, which otherwise rush down them cold, violent and unhealthy.
For a hall of assembly use the “D” or tribune plan, a half-circle closed by a straight side: it gives ample room to the audience, a central place to the speaker and scope for display in the architecture.
Make the sweating room of a bath circular, as high to the springing of its dome as it is wide, with an opening at the crown closed by a bronze disc that can be raised and lowered on chains to regulate the heat.
height to springing = width; oculus with a movable bronze shield
Lay the channel of an aqueduct with a steady fall of not less than a quarter of an inch in every hundred feet, cover it with a vault against the sun, and carry it through hills in tunnels and across valleys on arches.
minimum fall ≈ 1 : 4,800 (Morgan’s reading); Nîmes aqueduct: ≈ 12.6 m in ≈ 50 km ≈ 1 : 4,000
Draw the orchestra circle and inscribe in it four equilateral triangles at equal intervals; the side nearest the scene fixes the front of the scaena, a parallel through the centre fixes the front of the stage, and the angles on the auditorium side give the directions of the stairways.
12 vertices at 30°: 7 fix the stairs of the lower cavea, 5 fix the doors and passages of the scene; stage depth = r⁄2
Cite this page Chris Paton, “Keep the public buildings and porticoes clear”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/cth-public-porticoes. Text, drawings and models licensed under CC BY-NC 4.0.