The general rule that I've seen is that house numbers increase in increments of 100 (or occasionally 50) per block, with even numbers on one side and odd on the other. Depending on the number of houses on the block, there can be intervals of 2, 4, or 6 between house numbers - this generally results in "unused space" at the end of the block of numbers.
Often, but not always, blocks are numbered from some central location in a city - in the city of St. Louis, for example, buildings on east-west streets are numbered according to distance west of the Mississippi River, while those on north-south streets are numbered according to distance from Market Street, which runs more or less through the center of the city. Then, of course, one runs into problems with streets that no longer follow the grid (and the Mississippi, which is not conveniently straight nor north and south in direction). So there are adjustments to be made. And individual municipalities, which may be made up of only a few streets, might decide that they sound more "high class" if they have only two-digit house numbers rather than four-digit ones. So it's really a messy patchwork with only a very vague system to it. |
