Latin, the "laws of falling droplets," the iura stillicidiorum concern the stillicidium, rainwater that collects on the roofline of a house and runs off it. Documented by Vitruvius in his De architectura, this is one of the earliest building codes, and it particularly governed the construction of houses adjacent to one another or sharing a party wall.
The overhang of a taller building was required to give a measure of open-air distance from the next nearest roof, so that dripping water off one roof would not form stagnant pools in the depressions between the slopes of other nearby roofs. Roofs had to provide sufficient overhang that a man could stand at his own doorstep without being hit by rain or water dripping off neighbouring eaves onto his own roof. Vitruvius considered these considerations an extension of the adequate sewer drainage system of the city overall, and he encouraged - where possible - for roof overhangs to evenly divide the runoff of rainwater between the open-air cistern in the floor of the residential atrium, and the channels cut into the roadsides to help road waste and night soil be swept away into the sewer complex proper.
Cicero also discusses these laws briefly in Ad Marcum Brutum orator, where he relates them to the rights and expectations neighbours may have of each other for the sake of peaceful adjacent habitation, along with such rights as the right to unobstructed sunlight on one's house (a key feature of the passive solar design of the Roman domus, necessary for good ventilation as well as good heating and cooling), the right to not have shared party walls tampered, altered, or structurally compromised, nor for a great deal of noise to occur in rooms with a party wall, and the right to have unobstructed access to the street from one's residence.
Iron Noder 2018, 22/30