[Talk-GB] Import UK postcode data?

[ndrw6 at redhazel.co.uk]

On 04/10/2019 00:26, Dave F via Talk-GB wrote:
> I think you're missing the point. Most contributors believe postcodes 
> on buildings or property nodes, add quality to the OSM's database, but 
> object to the import of codepoint as it's just not accurate enough as 
> stated in this, & numerous other threads.

This is incorrect. CPO/ONSPD postcodes _are_ accurate, up to date and 
include all postcodes in the UK except NI. They are not complete 
(contain one and only one delivery point per postcode), which is pity, 
but that's not a reason not to use the ones that are available, which is 
still _far_ more that what we have in the database.

This may not be a perfect solution but the information CPO/ONSPD 
contains is still extremely useful for geocoding. Search for a postcode 
and you are _guaranteed_ to get an address in a close vicinity to a 
place you are looking for. How about not needing to start Google Maps 
when searching for a location on the go?

> There's no point in importing to stand alone nodes as deliveries are 
> destined for buildings. Adding to streets is also pointless for the 
> same reason plus they can have multiple postcodes.

Addresses on nodes are commonly used in the UK OSM. Many mappers prefer 
them over placing addresses on buildings. There are also many cases 
(POIs) where nodes are objectively better than buildings. So, no, there 
right and wrong solution here.

Besides, the main reason for importing these data is that we can get 
_all_ postcodes in the database. This gives users confidence that when 
they search for a postcode they will reliably get a result they are 
looking for. This is not possible when merging postcodes with buildings 
simply because we still have only a small fraction of buildings in the 
database.

By the way, I'm not against merging addr:postcode with buildings, that's 
exactly what I was doing myself when adding postcodes manually. However, 
this is not a process that can be automated (lack of buildings, single 
OSM buildings having more than one address/postcode). Based on my 
experience with mapping postcodes with CPO, I would recommend starting 
with an import and merge postcodes and buildings later.

ndrw6