User:Rjw62/UK Address Mapping

Table of suggested tags for basic addresses

Some draft thoughts on how to map the official UK address structure as defined by Royal Mail in its Postcode Address File (see the Users' Guide) to the addr=* OMS tags.

Address Component	Common Language Names	Official PAF Fields	OSM Tags
Premises	Flat/Unit Name and/or Number (within a named/numbered building)	Sub Building Name	?
	Building Name and/or Number	Building Name	addr:housename=*
		Building Number	addr:housenumber=*
Street	Sub Street	Dependent Thoroughfare Name Dependent Thoroughfare Descriptor	addr:street=*	addr:street=*
	Main Street	Thoroughfare Name Thoroughfare Descriptor		addr:parentstreet=*
Locality	hamlet village town suburb	Doubly Dependent Locality	addr:hamlet=* addr:village=* addr:suburb=* addr:town=*
		Dependent Locality
	Post Town	Post Town	addr:city=*
Postcode	Postcode	Postcode	addr:postcode=*

Notes / reasoning for items in the table

• Since the Post Town is required in every address, and takes a finite set of values, it makes sense to have a consistent tag for this. Rather than invent our own UK-specific tag, I feel the idea of a Post Town is close enough to the existing add:city tag to use this. Many UK post towns are indeed cities, and for the rest they are significant towns in the local area. As the wiki page says "The name of the city as given in postal addresses of the building/area." and "in some places the city in the address corresponds to the post office that serves the area rather than the actual city, if any, in which the building is located"
• If we are using addr:city for the Post Town, then we need additional tags for the smaller settlements (dependent and doubly dependent localities) that can also appear in addresses. Multiple key names are needed here as there can be up to two additional localities in an address. addr:hamlet and addr:suburb already exist in OSM. It would seem to make sense to introduce similar named settlement type tags for the remaining UK concepts of towns and villages. Hence the recommendation to use an appropriate combination of addr:hamlet, addr:village, addr:suburb and addr:town for any dependent and doubly dependent localities.
• When there are two street names given in an address, these are recorded as the Thoroughfare and Dependent Thoroughfare in the PAF. However, when considering an address, it will be the Dependent Thoroughfare which the house number/name will correspond to. I think it therefore makes more sense to record this under the standard addr:street tag, and introduce a new tag for the parent Thoroughfare: addr:parentstreet. This method has the advantage that tools/users that are not aware of addr:parentstreet, will still get a valid "addr:housenumber, addr:street" combination.

Issues still to resolve

Sub-divided buildings

How do we tag a property that is either numbered or named, but is part of a larger building that also have a number or name. e.g. "1, Humber Lodge" or "2, Station Cottages". We cannot just use addr:housenumber and addr:housename, as that wouldn't distinguish things from the case were the number and the name both apply to the same property (i.e. house number 7 is also given the name "Bramble Cottage".

Business parks, retail parks, hospital campuses, housing estates, etc.

There are often cases of a business or retail park will appear in an address. There may be a road name within the park, or the park may be located on a road, or even both. What tag do we use for this, and how do we ensure correct ordering relative to any street names also given? Potentially, we could use addr:place (which is defined to be used instead of addr:street in similar circumstances) for this, with addr:parentstreet and addr:substreet for road names outside and within respectively.