[Talk-GB] OSM UK address project: tags

[Sarah Hoffmann]

Hi,

answering to Tom and Rob in one mail

Rob Nickerson wrote:

> see that cleaned up in the UK, it is unrealistic to change it globally. If
> it is assumed to be _after_ the street in the global usage then clearly the
> UK is going to need a new tag as it is not possible to get our address
> system into the existing (globally used) addr:* tags. :-(

To be clear, It'still a misstagging to have both tags on the same
object. I'm just saying that from a data consumer point of view you get
the best results when you handle the addrlace tag like an addr:suburb
tag when both appear after all.

To give a bit of historic background on the addr:place tag: when the
first addresses were mapped in OSM we started out with two basic
assumptions: 1. most addresses are street addresses (i.e. a housenumber
that refers to the closest street) and 2. a postal address is usually
the same as the gegographic location. People were aware that there are
exceptions, which is why there are many addr:* tags. Still, the
assumption was that in 99% of the cases you can add a addr:housenumber
and be done with it. To compute the address find the closest street,
village centre, county etc geographically. The result of this decision
was that you can't just map an address that doesn't contain a street by
leaving out the addr:street tag. Because the absence of the tag is
defined as: use the closest street instead. That's where the addr:place
tag came in. It was invented to clearly signal the data consumer: this
address does not contain a street. Do not include the closest street in
the address. Start the address with this place after the housenumber
instead.

And that's why the addr:street and addr:place tags should not be on the
same object. It's sending mixed messages.

> On “But so far I have yet to see two streets as an official part of the
> address” see example E provided by Robert Whittaker.

I meant: outside the UK.

The E example really is a wicked one. I suspect that the street names
within Bently Country Park are not really official with regard to the
address. Holiday parks like to do their own fake village layout
sometimes. I've seen that in other countries as well. So how about
that:

 addr:unit = 1 Beech Way
 addr:substreet = Bentley Country Park
 addr:street = Flag Hill

(or use addr:housename instead of addr:substreet for the established
schema, altough it is stretching the meaning of the tag a bit)

Tom Crocker wrote:
> Can you add something about room / flat numbers to the algorithm (or do you
> think we should use unit)?

As I've used addr:unit above: I'd consider addr:unit and addr:flat
one level lower than addr:housenumber and addr:housename. So there is
a difference between

  addr:housenumber = 14
  addr:housename = The Nest
  addr:street = Main Street

and

  addr:unit = 14
  addr:housename = The Nest
  addr:street = Main Street

The former I'd read as 'The Nest at Main Street 14' the latter as
'The Nest 14 at Main St'.

> *Sarah*, do you have a suggestion (or know what's been used elsewhere) for
> building complexes off a street?

This is still a bit of a gray area.

In most cases that I've seen, the name of the buidling complex replaces
the street in the address. The building complex can than be mapped as a
named landuse=residental and the address with addr:place=Building
complex.

For single buildings that include the street in the address:
  addr:unit = X
  addr:housename = Building Complex
  addr:street = My Street

It all depends on the specific situation.

Sarah