ELi5 – How are street adresses determined / how do they get numbered?
In: 59
There’s like three systems that I’m aware of. The first is where there is no universal datum. They basically just make the first house on the left side of the street “1” and the first on the right side “2” and repeat that pattern for the whole street. This is common in places without a grid system where there aren’t a lot of lengthy continuous streets.
The second system uses a north/south and east/west datum. The addresses start at 1 and just go up sequentially as they get further from the datum. So 45 West Park Ave would be the 45th house west of the datum on Park Ave. Though, again, they normally alternate by side of the street so 45 would really be the 23rd house west of the datum on the left side of the street.
The third system is what was once known as the Philadelphia system. There the final two digits are your house number but everything before that is the block number. These also correlate with street numbers (eg. 1st Street, 2nd Avenue, etc.). So 201 W Park Avenue would mean heading west on Park Ave you’d be the first house on the left after passing 2nd Street. This system allows for up to 100 houses on a block but it’s normally far less than that. So the house on the opposite side of 2nd Street might be 113 Park Ave.
UK – The local council planning team get the plot numbers from the developer and come up with a naming scheme and numbering on their own.
My local council decided to name the roads in the new build area near me after locals that were killed in WW2 – very nice. However, they didn’t seem to keep a list of ones they had already used and ended up using the same names multiple times in the same estate e.g. Smith Crescent, Smith Road, Smith Close
That varies from city to city.
A common system in countries that use the metric system is to use the distance in meters from the beginning of the street, rounded off to the closest even or odd numbers, using even numbers for the right side and odd numbers for the left side of the street.
This is a pretty good list of how bonkers addresses can be: https://www.mjt.me.uk/posts/falsehoods-programmers-believe-about-addresses/
Depends on where you are.
In city limits, especially with planned new roads and development, they are often just numbered with odds on one side, and evens on the other, just numbered up from 1 to whatever the road finishes at.
In rural areas, the house numbers are more often reflective of the distance from the end of the road.
By in laws live in a rural area, they house number is an indication of how far they are from the start of the road.
Historically in some places in Europe the numbers were given out by Napoleon when he conquered places. He changed the local systems like naming some special places to the number system used in Paris.
Just to add to the commonly mentioned rules for even/odd numbering I’ve seen some suburban areas in Canada where instead of using blocks assigned a group of numbers (usually 100) they have a numbering scheme that is simply in approximate meters. So a house with address 1200 would be 1k from address 2200. It’s also not uncommon for property owners to apply to the city for an address numbering change, especially those from a culture with numerological superstitions.
In my experience where I’ve lived in the US, there’s basically a center point where address start in the tens, and every block away they go up by 100. So the first block could have 1, 2, 3, etc, then the next block would have 101, 102, 103, etc.
The town where I learned to drive also had numbers for most of the roads, with streets going NS and avenues going WE. So if you were going to 1105 7th Ave NW, you knew it was on the 7th Ave north of main street and not the 7th Ave south, it was on the western side of town, and it was between 11th St and 12th St.
Where ever you are at if you go in descending order. You will find the center of the city. Which is usually the 100 block. After passing it will ascend in the other direction. Opposite of where you were. So North/South and East/West.
So it’s mostly a square grid moving out from the center with 4 quadrants. Blocks are typically in 100’s or 1000’s. Odd addresses on one side. Even on the other.
Someone might be interested in an European perspective:
1. Naming conventions vary a lot between EU countries but there are some patterns you may encounter like grouping streets by giving them “related” names. E.g. groups of streets having flower names for example (Rose street, Orchid street, etc) or names of writers, historians, trees, etc. you get the idea.
2. Streets and avenues have even numbers the right side and odds on the left side and they start counting from the end that’s closest to the townhall.
3. Squares count clockwise using consecutive numbers (1,2,3,4…)
4. If a plot gets shared between 2 or more buildings – like Orchid street 4, ends up with 2 houses on it, they become orchid street 4A and 4B
5. If the opposite happens, a property stretches around various plots, it will end up with an adrees like “Rose street 4-7” – stretching over 3 plots as there would normally be numbers 3, 5 and 7.
Latest Answers