House numbering is the system of giving a unique number to each building in a street or area, with the intention of making it easier to locate a particular building. The house number is often part of a postal address. The term describes the number of any building (residential or commercial) with a letterbox, or even a vacant lot. House numbering also serves a public safety function; visible house numbers allow emergency services to locate properties more quickly, and both the International Fire Code and National Fire Protection Association fire codes require buildings to display address numbers that are legible and visible from the street.
House numbering schemes vary by location, and in many cases even within cities. In some areas of the world, including many remote areas, houses are named but are not assigned numbers.
In many countries, the house number follows the name of the street; but in anglophone and francophone countries, the house number normally precedes the name of the street.
History
A house-numbering scheme was in use on the Pont Notre-Dame in Paris in 1463, covering 68 houses. However, it is unclear whether these numbers served as an addressing system or as a way of cataloguing property. A numbering system was adopted in the Fuggerei in Augsburg in 1519, but its original purpose is also unclear.
In the 18th century, street numbering schemes were applied across Europe, to aid in administrative tasks and the provision of services such as postal delivery. The New View of London reported in 1708 that "at Prescott Street, Goodman's Fields, instead of signs, the houses are distinguished by numbers". Parts of the Paris suburbs were numbered in the 1720s; the houses in the Jewish quarter in the city of Prague in the Austrian Empire were numbered in the same decade to aid the authorities in the conscription of the Jews.
House numbering gained momentum in the mid-18th century, especially in Prussia, where authorities were ordered to "affix numbers on the houses ... in little villages on the day before the troops march in". In the 1750s and 60s, house numbering on a large scale was applied in Madrid, London, Paris, and Vienna, as well as many other cities across Europe. On 1 March 1768, King Louis XV of France decreed that all French houses outside Paris affix house numbers, primarily for tracking troops quartered in civilian homes. The French Revolutionary Wars and Napoleonic Wars spread the French house numbering system across large areas of Europe.
The adoption of house numbers sometimes gave rise to resistance. In Litomyšl in 1770, house numbers that had been imposed for military registration were covered in dung or partly gouged out with an iron bar. In 1782 in Geneva, nearly 150 house numbers were erased.
Due to the gradual development of house numbering and street addressing schemes, reform efforts occur periodically. For instance, some US cities commenced efforts to improve their schemes in the late 19th century.
Australia and New Zealand
In Australia and New Zealand, the current standard (Australia/New Zealand joint standard AS/NZS 4819:2011 – Rural & Urban Addressing) is directed at local governments that have the primary responsibility for addressing and road naming. The standard calls for lots and buildings on newly-created streets to be assigned odd numbers (on the left) and even numbers (on the right) when facing in the direction of increasing numbers (the European system), thereby reflecting existing common practice. It first came into force in 2003 under AS/NZS 4819:2003 – Geographic Information – Rural & Urban Addressing. An exception may occur where the road forms part of the boundary between different council areas or cities. One example of this is Underwood Road in Rochedale South, part of which is divided between Logan City and the City of Brisbane.
Where a plot of land, such as No. 9, is divided into parts, the sequence might be 7, 9, 9A, 11, 13. Conversely, should plots of land be combined such as 51, 53, 55, the numbers might run as 49, 51–55, 57. An older form of 9A is 9½.
In New South Wales and South Australia, the vast majority of streets were numbered when the land titles were created, with odd numbers assigned to houses on the right of the street when facing the direction along which numbers increase. There is no plan to reassign these numbers.
On some long urban roads (e.g., Parramatta Road in Sydney) numbers ascend until the road crosses a council or suburb boundary, then start again at 1 or 2, where a street sign gives the name of the relevant area – these streets have repeating numbers. In semi-rural and rural areas, where houses and farms are widely spaced, a numbering system based on tens of metres or (less commonly) metres has been devised. Therefore, a farm from the start of the road on the right-hand side would be numbered 230."Street Addressing Working Group and the National Street Addressing Standard" . Intergovernmental Committee on Survey and Mapping. 19 March 2008. Retrieved 24 February 2010.
Walcha, in the New England district of northern New South Wales, has a unique numbering system which differs from the rest of the state. The town is located at the crossroads of the Oxley Highway and Thunderbolts Way. All properties on east–west running streets have a 'W' or 'E' appended to the number, signifying that the property lies to the west (or east) of Thunderbolts Way. Similarly, houses in north–south running streets have an 'N' or 'S' appended to the house number, signifying that the property lies north (or south) of the Oxley Highway.
Ballarat Central, Victoria, uses the US system of increasing house numbers by 100 after a major cross street. Streets are designated North or South depending upon their relative position to Sturt Street.
The number system will always start with No. 1 or No. 2 at the datum point of the street, with number 1 typically being on the left side of the street.
East Asia
In Japan, a city is divided into small numbered zones. The houses within each zone are then labelled in the order in which they were constructed, or clockwise around the block. This system is comparable to the system of sestieri (sixths) used in Venice.
South Korea formerly used a similar system, but in 2011 adopted a new address format based on street numbering, similar to Western countries. Large apartment complexes often share a single street address, but individual buildings within the complex are identified by internal building numbers, typically followed by the suffix dong ("동"， from Chinese 棟 ), meaning "building" or "block". For example, "101동" refers to Building 101 within the complex. These identifiers are widely used for navigation and postal services, even though they are not part of the official street address.
Separately, dong (same "동"， but from different Chinese 洞 ) also refers to a neighbourhood or administrative district within a city, used in both legal and administrative contexts.
In Hong Kong, a former British colony, the European norm for numbering houses on one side of the street with odd numbers, and the other side with even numbers, is generally followed. Some roads or streets along the coastline may however have numbering only on one side, even if the opposite side is later reclaimed. These roads or streets include Ferry Street, Connaught Road West, and Gloucester Road.
Most mainland Chinese cities use the European system, with odd numbers on one side of the road and even numbers on the opposite side. In high-density old Shanghai, a street number may be either a hao ("号" hào) or nong ("弄" nòng/lòng), both of them being numbered successively. A hao refers to a door rather than a building, for example, if a building with the address 25 Wuming Rd is followed by another building, which has three entrances opening to the street, the latter will be numbered as three different hao, from 27 to 29 Wuming Rd.
A nong, sometimes translated as "lane", refers to a block of buildings. So if in the above example the last building is followed by an enclosed compound, it will have the address "lane 31, Wuming Rd". A nong is further subdivided within its own hao, which do not correlate with the hao of the street, so the full address of an apartment within a compound may look like "Apartment 5005, no. 7, lane 31, Wuming Rd".
In Taiwan, the European system is used in cities, and is mostly the same as in mainland Chinese cities and Hong Kong. Longer roads are usually divided into several sections to prevent the road having too many numbers (normally more than 1000). In rural areas, the village or settlement name is used in house numbering, where numbering norms are not certain. A xiang ("巷" xiàng, translated as "lane") indicates a branch from a main road; and a nong ("弄" nòng/lòng, translated as "alley") indicates a branch from a xiang. For many reasons such as new establishment of buildings or several apartments in a building, the zhi ("之" zhī, normally simply translated as a hyphen, "–") is used.
Southeast Asia The most common street address formats in Vietnam are:
A number followed by the street name, for example "". This is the most basic, most common format. A number with an alphabetic suffix: "", "", etc. This format occurs when a property is numbered 123 but later subdivided into two houses with different addresses. If the house lies on an hẻm/ngõ (alley), the alley number is combined with the house number: for example, in "", 123 is the alley's address, and 3 is the house number on that alley. More complex house numbers may occur on alleys that branch from other alleys or properties on alleys are subdivided, for example "" or "". An extreme example would be "", which is located on 3rd alley off 12th alley off 14th alley off 7th alley off 182nd street.
Another scheme is based on residential areas called . A is addressed by house number, road, and , for example "". Some localities still use an older address format based on neighbourhood (): for example, in "", 7A is the neighbourhood number. This confusing format is being gradually phased out in favour of the more modern formats above.
West Asia
Generally in Iran and especially in the capital Tehran odd numbers are all on one side and the even numbers opposite along streets. Infrequently, this style confuses people because this is not how it works everywhere in the city and sometimes the numbers get intertwined with each other. In the rural parts, some houses have no number at all and some have their owner's details as the number instead. In some cases, using the number 13 is skipped replacing it with equivalents such as: 12+1 or 14−1 .
Northern and Western Europe
In Europe the most common house numbering scheme, in this article referred to as the "European" scheme, is to number each plot on one side of the road with ascending odd numbers, from 1, and those on the other with ascending even numbers, from 2 (or sometimes 0). The odd numbers are usually on the left side of the road, looking in the direction in which the numbers increase.
Where additional buildings are inserted or subdivided, these are often suffixed a, b, c, etc. (in Spain, France and Afragola until 2001, bis, ter, quater, quinquies etc.). Where buildings are later combined, one of the original numbers may be used, the numbers may be combined ("13/15"), or the numbers may be used as a given range (e.g. "13–17"; not to be construed as including the even numbers 14 and 16). Buildings with multiple entrances may have a single number for the entire building or a separate number for each entrance.