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Postcodes

phoenix830-2
Hello

I have started added properties in my local area from my own knowledge. Either gathered from my own residing or from friends and from lots of walks.

I want to add postcodes but I am aware of issues with this being copyrighted material.

I have come across https://postcodes.io which states it is from open sources. I have contacted them here https://ideal-postcodes-support.herokuapp.com/channel/support .

They have confirmed that this data is released under the Open Government Licence http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ .

I understand the complications will be huge if I use the wrong data source so I simply want clarification if the postcodes found on this site would be safe and legal to do so.

I am not bulk adding these (I do not have the technical knowledge or time) I am just adding postcodes to properties as I add them.

Kind Regards

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Re: Postcodes

Tom Hughes-3
On 09/11/2018 09:09, Phoenix830 wrote:

> I want to add postcodes but I am aware of issues with this being
> copyrighted material.

Add them to what exactly?

> I have come across https://postcodes.io which states it is from open
> sources. I have contacted them here
> https://ideal-postcodes-support.herokuapp.com/channel/support .
>
> They have confirmed that this data is released under the Open Government
> Licence
> http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ .

That data set only gives a centroid for each post code though, it
doesn't tell you what postcode a particular building has.

> I am not bulk adding these (I do not have the technical knowledge or
> time) I am just adding postcodes to properties as I add them.

So how are you working out which postcode to use? Sometimes it is
fairly obvious from the centroid location but it often isn't.

Tom

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Re: Postcodes

Paul Berry
Would the etiquette here be to tag the objects with source=local knowledge if you happen to know the postcode without looking it up (or it's on signage, etc)?

Regards,
Paul

On Fri, 9 Nov 2018 at 09:38, Tom Hughes <[hidden email]> wrote:
On 09/11/2018 09:09, Phoenix830 wrote:

> I want to add postcodes but I am aware of issues with this being
> copyrighted material.

Add them to what exactly?

> I have come across https://postcodes.io which states it is from open
> sources. I have contacted them here
> https://ideal-postcodes-support.herokuapp.com/channel/support .
>
> They have confirmed that this data is released under the Open Government
> Licence
> http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ .

That data set only gives a centroid for each post code though, it
doesn't tell you what postcode a particular building has.

> I am not bulk adding these (I do not have the technical knowledge or
> time) I am just adding postcodes to properties as I add them.

So how are you working out which postcode to use? Sometimes it is
fairly obvious from the centroid location but it often isn't.

Tom

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Re: Postcodes

David Woolley
In reply to this post by phoenix830-2
On 09/11/18 09:09, Phoenix830 wrote:
> They have confirmed that this data is released under the Open Government
> Licence
> http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ .
>


There is a gotcha in the OGL regarding restricted upstream sources, so
OGL is probably not enough.  In any case, if you are only dealing with
centroids, I think many have been mapped already, and, if not, you
should use the OS Open Data source for those, not take them from a site
whose business model depends on accumulating their own database of
detailed postcode information.

As pointed out, you cannot say that a particular property has a
particular postcode just because the nearest postcode centroid has that
postcode.  You need to individually verify each property.



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Re: Postcodes

David Woolley
On 09/11/18 11:34, David Woolley wrote:
> if you are only dealing with centroids, I think many have been mapped
> already,

<https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
indicates that at least 2500 have been mapped.

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Re: Postcodes

Dan S
In reply to this post by Paul Berry
Op vr 9 nov. 2018 om 10:41 schreef Paul Berry <[hidden email]>:
>
> Would the etiquette here be to tag the objects with source=local knowledge if you happen to know the postcode without looking it up (or it's on signage, etc)?

Hi - two slightly different things in your question there - the
convention is, as far as I understand it, to use
source=local_knowledge if you happen to know it from being there
yourself or a local tells you, and source=survey if you see it on
signage.

As far as I know, there's some disagreement about whether and how
"disembodied" postcodes should be added, but I do often add postcodes
e.g. on specific shops or addresses where I've got it first-hand (e.g.
from the shop window)

Best
Dan


> On Fri, 9 Nov 2018 at 09:38, Tom Hughes <[hidden email]> wrote:
>>
>> On 09/11/2018 09:09, Phoenix830 wrote:
>>
>> > I want to add postcodes but I am aware of issues with this being
>> > copyrighted material.
>>
>> Add them to what exactly?
>>
>> > I have come across https://postcodes.io which states it is from open
>> > sources. I have contacted them here
>> > https://ideal-postcodes-support.herokuapp.com/channel/support .
>> >
>> > They have confirmed that this data is released under the Open Government
>> > Licence
>> > http://www.nationalarchives.gov.uk/doc/open-government-licence/version/2/ .
>>
>> That data set only gives a centroid for each post code though, it
>> doesn't tell you what postcode a particular building has.
>>
>> > I am not bulk adding these (I do not have the technical knowledge or
>> > time) I am just adding postcodes to properties as I add them.
>>
>> So how are you working out which postcode to use? Sometimes it is
>> fairly obvious from the centroid location but it often isn't.
>>
>> Tom
>>
>> --
>> Tom Hughes ([hidden email])
>> http://compton.nu/
>>
>> _______________________________________________
>> Talk-GB mailing list
>> [hidden email]
>> https://lists.openstreetmap.org/listinfo/talk-gb
>
> _______________________________________________
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> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-gb

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Re: Postcodes

Tom Hughes-3
In reply to this post by David Woolley
On 09/11/2018 11:44, David Woolley wrote:
> On 09/11/18 11:34, David Woolley wrote:
>> if you are only dealing with centroids, I think many have been mapped
>> already,
>
> <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
> indicates that at least 2500 have been mapped.

Yes, but it's a stupid idea, so please don't...

Tom

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Re: Postcodes

Adam Snape
Hi,

I agree with not mapping the centroids but...

Is it the case that the centroids are always placed on a building which falls under that postcode? If so, wouldn't it be okay to tag the building with the appropriate postcode?

Another idea: Given that postcodes (with few exceptrions) apply to only one street, would it be acceptable to add the postcode tag to the street where there is only one centroid on the street?

Kind regards,

Adam

On Fri, 9 Nov 2018 at 12:26, Tom Hughes <[hidden email]> wrote:
On 09/11/2018 11:44, David Woolley wrote:
> On 09/11/18 11:34, David Woolley wrote:
>> if you are only dealing with centroids, I think many have been mapped
>> already,
>
> <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
> indicates that at least 2500 have been mapped.

Yes, but it's a stupid idea, so please don't...

Tom

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Re: Postcodes

David Woolley
If centroid has the plain (mathematical) meaning of the word, it will
only fall exactly on the building centre if there is only one building
in the postcode area.

In practice the building nearest the centroid might have its own
postcode, so you can't rely on the nearest building to the centroid
having that postcode.

There are, at least theoretically (e.g. a C shaped postcode) where the
centroid is in an adjoining postcode.  I imagine you would get this if
there was a cul-de-sac projecting into a crescent that was small enough
to have one post code.

On 09/11/18 13:12, Adam Snape wrote:

> Hi,
>
> I agree with not mapping the centroids but...
>
> Is it the case that the centroids are always placed on a building which
> falls under that postcode? If so, wouldn't it be okay to tag the
> building with the appropriate postcode?
>
> Another idea: Given that postcodes (with few exceptrions) apply to only
> one street, would it be acceptable to add the postcode tag to the street
> where there is only one centroid on the street?
>
> Kind regards,
>
> Adam
>
> On Fri, 9 Nov 2018 at 12:26, Tom Hughes <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>     On 09/11/2018 11:44, David Woolley wrote:
>      > On 09/11/18 11:34, David Woolley wrote:
>      >> if you are only dealing with centroids, I think many have been
>     mapped
>      >> already,
>      >
>      > <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
>      > indicates that at least 2500 have been mapped.
>
>     Yes, but it's a stupid idea, so please don't...
>
>     Tom
>
>     --
>     Tom Hughes ([hidden email] <mailto:[hidden email]>)
>     http://compton.nu/
>
>     _______________________________________________
>     Talk-GB mailing list
>     [hidden email] <mailto:[hidden email]>
>     https://lists.openstreetmap.org/listinfo/talk-gb
>
>
>
> _______________________________________________
> Talk-GB mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-gb
>


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Re: Postcodes

Philip Barnes
On Fri, 2018-11-09 at 13:26 +0000, David Woolley wrote:

> If centroid has the plain (mathematical) meaning of the word, it
> will
> only fall exactly on the building centre if there is only one
> building
> in the postcode area.
>
> In practice the building nearest the centroid might have its own
> postcode, so you can't rely on the nearest building to the centroid
> having that postcode.
>
> There are, at least theoretically (e.g. a C shaped postcode) where
> the
> centroid is in an adjoining postcode.  I imagine you would get this
> if
> there was a cul-de-sac projecting into a crescent that was small
> enough
> to have one post code.
>
I live in such a road, it is big enough to have different postcodes for
odd and even numbers. The two centoids are very close together and it
would not be possible to determine which is which without local
knowledge.

Phil (trigpoint)


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Re: Postcodes

Adam Snape
In reply to this post by David Woolley
Hi,

I ask because the 'centroids' do not appear to be centroids in a pure mathematical sense, they always appear to be placed on a building, never in open space. Now, if this were merely been done by attributing the centroid to the nearest building regardless of whether it actually belongs to the postcode or not, it would serve no purpose. It seems far more likely that it would be attributed to the nearest building belonging to that postcode. If this is the case then it gives us a way of tying these centroids to an actual building within each postcode area and that gives us something tangible to map. Can anybody suggest whether I'm onto something here?

Kind regards,

Adam

On Fri, 9 Nov 2018 at 13:27, David Woolley <[hidden email]> wrote:
If centroid has the plain (mathematical) meaning of the word, it will
only fall exactly on the building centre if there is only one building
in the postcode area.

In practice the building nearest the centroid might have its own
postcode, so you can't rely on the nearest building to the centroid
having that postcode.

There are, at least theoretically (e.g. a C shaped postcode) where the
centroid is in an adjoining postcode.  I imagine you would get this if
there was a cul-de-sac projecting into a crescent that was small enough
to have one post code.

On 09/11/18 13:12, Adam Snape wrote:
> Hi,
>
> I agree with not mapping the centroids but...
>
> Is it the case that the centroids are always placed on a building which
> falls under that postcode? If so, wouldn't it be okay to tag the
> building with the appropriate postcode?
>
> Another idea: Given that postcodes (with few exceptrions) apply to only
> one street, would it be acceptable to add the postcode tag to the street
> where there is only one centroid on the street?
>
> Kind regards,
>
> Adam
>
> On Fri, 9 Nov 2018 at 12:26, Tom Hughes <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>     On 09/11/2018 11:44, David Woolley wrote:
>      > On 09/11/18 11:34, David Woolley wrote:
>      >> if you are only dealing with centroids, I think many have been
>     mapped
>      >> already,
>      >
>      > <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
>      > indicates that at least 2500 have been mapped.
>
>     Yes, but it's a stupid idea, so please don't...
>
>     Tom
>
>     --
>     Tom Hughes ([hidden email] <mailto:[hidden email]>)
>     http://compton.nu/
>
>     _______________________________________________
>     Talk-GB mailing list
>     [hidden email] <mailto:[hidden email]>
>     https://lists.openstreetmap.org/listinfo/talk-gb
>
>
>
> _______________________________________________
> Talk-GB mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-gb
>


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Re: Postcodes

Adam Snape
In reply to this post by Philip Barnes
Hi,

I'm not on about extrapolating postcodes for other buildings on a street, but we should be able to map the postcode of building on which the centroid is placed, shouldn't we? Zooming in should allow us to see which building a centroid is on. 

Kind regards,

Adam

On Fri, 9 Nov 2018 at 13:44, Philip Barnes <[hidden email]> wrote:
On Fri, 2018-11-09 at 13:26 +0000, David Woolley wrote:
> If centroid has the plain (mathematical) meaning of the word, it
> will
> only fall exactly on the building centre if there is only one
> building
> in the postcode area.
>
> In practice the building nearest the centroid might have its own
> postcode, so you can't rely on the nearest building to the centroid
> having that postcode.
>
> There are, at least theoretically (e.g. a C shaped postcode) where
> the
> centroid is in an adjoining postcode.  I imagine you would get this
> if
> there was a cul-de-sac projecting into a crescent that was small
> enough
> to have one post code.
>
I live in such a road, it is big enough to have different postcodes for
odd and even numbers. The two centoids are very close together and it
would not be possible to determine which is which without local
knowledge.

Phil (trigpoint)


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Re: Postcodes

sk53.osm
In reply to this post by Adam Snape
I'm pretty sure that the "centroid" is allocated to the nearest delivery point in the postcode which places it over a building. See my (now rather) old blog post from 2013, and the note by Jenni Tennison. A caveat is, of course, that the Land Registry Prices Paid data proved to be an open data mirage.

Please remember that Nominatim has a table (not recently updated) of all postcode centroid which are used for searches. These usually show as AB10 2## or similar and are at a lowish zoom level.

Judging by taginfo stats we now have around 8-10% of all postcodes mapped, and Robert Whittaker's site suggests over 10%, so better than in 2013, but nowhere near the level we could get if we adopted a sustained campaign to use what information we have.

Personally, I add addr:postcode to streets when: a) it is clear that all properties share a postcode, but individual properties have not been mapped; and b) when the local authority includes the full postcode on the streetname sign (e.g., Gedling & Rushcliffe). In the former case this should be regarded as an iterative step towards the desired position of individually mapped addresses; in the latter it reflects an on-the-ground rule.

The available sets of open data which can be used to resolve postcodes are: Food Hygiene (the best, easiest to resolve, coverage of the whole UK - even Rutland); Companies House Open Data (surprisingly useful even in areas of social housing); the National Register of Social Housing (NROSH, not updated since 2011, but still very useful); CQC (medical practices, care homes etc). I haven't looked to see how many postcodes are covered by these in total, but it should be a reasonable proportion of the total. If you aren't aware Will Phillips OSM-Nottingham site does allow searching of various open data sets across the UK (I would recommend searching only in the viewport, so you need to zoom out and in to the target area). The quickest way to ensure at least one address is mapped for a given postcode is using Greg's FHRS tools.

Jerry

On Fri, 9 Nov 2018 at 13:44, Adam Snape <[hidden email]> wrote:
Hi,

I ask because the 'centroids' do not appear to be centroids in a pure mathematical sense, they always appear to be placed on a building, never in open space. Now, if this were merely been done by attributing the centroid to the nearest building regardless of whether it actually belongs to the postcode or not, it would serve no purpose. It seems far more likely that it would be attributed to the nearest building belonging to that postcode. If this is the case then it gives us a way of tying these centroids to an actual building within each postcode area and that gives us something tangible to map. Can anybody suggest whether I'm onto something here?

Kind regards,

Adam

On Fri, 9 Nov 2018 at 13:27, David Woolley <[hidden email]> wrote:
If centroid has the plain (mathematical) meaning of the word, it will
only fall exactly on the building centre if there is only one building
in the postcode area.

In practice the building nearest the centroid might have its own
postcode, so you can't rely on the nearest building to the centroid
having that postcode.

There are, at least theoretically (e.g. a C shaped postcode) where the
centroid is in an adjoining postcode.  I imagine you would get this if
there was a cul-de-sac projecting into a crescent that was small enough
to have one post code.

On 09/11/18 13:12, Adam Snape wrote:
> Hi,
>
> I agree with not mapping the centroids but...
>
> Is it the case that the centroids are always placed on a building which
> falls under that postcode? If so, wouldn't it be okay to tag the
> building with the appropriate postcode?
>
> Another idea: Given that postcodes (with few exceptrions) apply to only
> one street, would it be acceptable to add the postcode tag to the street
> where there is only one centroid on the street?
>
> Kind regards,
>
> Adam
>
> On Fri, 9 Nov 2018 at 12:26, Tom Hughes <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>     On 09/11/2018 11:44, David Woolley wrote:
>      > On 09/11/18 11:34, David Woolley wrote:
>      >> if you are only dealing with centroids, I think many have been
>     mapped
>      >> already,
>      >
>      > <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
>      > indicates that at least 2500 have been mapped.
>
>     Yes, but it's a stupid idea, so please don't...
>
>     Tom
>
>     --
>     Tom Hughes ([hidden email] <mailto:[hidden email]>)
>     http://compton.nu/
>
>     _______________________________________________
>     Talk-GB mailing list
>     [hidden email] <mailto:[hidden email]>
>     https://lists.openstreetmap.org/listinfo/talk-gb
>
>
>
> _______________________________________________
> Talk-GB mailing list
> [hidden email]
> https://lists.openstreetmap.org/listinfo/talk-gb
>


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Re: Postcodes

Will Phillips
On 09/11/2018 14:44, SK53 wrote:

> The available sets of open data which can be used to resolve postcodes
> are: Food Hygiene (the best, easiest to resolve, coverage of the whole
> UK - even Rutland); Companies House Open Data (surprisingly useful
> even in areas of social housing); the National Register of Social
> Housing (NROSH, not updated since 2011, but still very useful); CQC
> (medical practices, care homes etc). I haven't looked to see how many
> postcodes are covered by these in total, but it should be a reasonable
> proportion of the total. If you aren't aware Will Phillips
> OSM-Nottingham site does allow searching of various open data sets
> across the UK (I would recommend searching only in the viewport, so
> you need to zoom out and in to the target area). The quickest way to
> ensure at least one address is mapped for a given postcode is using
> Greg's FHRS tools.

The datasets used by OSM Nottingham currently include 1,278,680 unique
postcodes. I've not checked how many of these are valid postcodes.
Sources such as Companies House don't validate their addresses, so this
total will certainly include some proportion that are incorrect.

There are 1.76 million postcodes in the UK (from Codepoint), so the open
data covers at most 73% of the total.

Regards,
Will





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Re: Postcodes

Adam Snape
In reply to this post by sk53.osm

Hi

To clarify the question I was asking earlier, this is what the OS say:

"Code-Point Open is created by taking the average of the coordinates of all the individual addresses in a postcode (provided we have any of sufficient quality), then snapping to the nearest of those addresses. Code-Point Open then delivers the coordinates of that address, as representative of the whole postcode, to a resolution of 1 metre.

The accuracy of a Code-Point Open record could be expressed as, that the coordinated position will always be within the notional geographical extent of the postcode."

They do also note that centroids for new postcodes where the buildings themselves have yet to be surveyed will be given a temporary approximate position which should be noted as such in the metadata.

My conclusion from this is that we can safely map postcodes to the building where their centroids are placed, perhaps avoiding doing so (or adding FIXMEs) on brand new developments.

Kind regards,

Adam


On Fri, 9 Nov 2018, 14:45 SK53 <[hidden email] wrote:
I'm pretty sure that the "centroid" is allocated to the nearest delivery point in the postcode which places it over a building. See my (now rather) old blog post from 2013, and the note by Jenni Tennison. A caveat is, of course, that the Land Registry Prices Paid data proved to be an open data mirage.

Please remember that Nominatim has a table (not recently updated) of all postcode centroid which are used for searches. These usually show as AB10 2## or similar and are at a lowish zoom level.

Judging by taginfo stats we now have around 8-10% of all postcodes mapped, and Robert Whittaker's site suggests over 10%, so better than in 2013, but nowhere near the level we could get if we adopted a sustained campaign to use what information we have.

Personally, I add addr:postcode to streets when: a) it is clear that all properties share a postcode, but individual properties have not been mapped; and b) when the local authority includes the full postcode on the streetname sign (e.g., Gedling & Rushcliffe). In the former case this should be regarded as an iterative step towards the desired position of individually mapped addresses; in the latter it reflects an on-the-ground rule.

The available sets of open data which can be used to resolve postcodes are: Food Hygiene (the best, easiest to resolve, coverage of the whole UK - even Rutland); Companies House Open Data (surprisingly useful even in areas of social housing); the National Register of Social Housing (NROSH, not updated since 2011, but still very useful); CQC (medical practices, care homes etc). I haven't looked to see how many postcodes are covered by these in total, but it should be a reasonable proportion of the total. If you aren't aware Will Phillips OSM-Nottingham site does allow searching of various open data sets across the UK (I would recommend searching only in the viewport, so you need to zoom out and in to the target area). The quickest way to ensure at least one address is mapped for a given postcode is using Greg's FHRS tools.

Jerry

On Fri, 9 Nov 2018 at 13:44, Adam Snape <[hidden email]> wrote:
Hi,

I ask because the 'centroids' do not appear to be centroids in a pure mathematical sense, they always appear to be placed on a building, never in open space. Now, if this were merely been done by attributing the centroid to the nearest building regardless of whether it actually belongs to the postcode or not, it would serve no purpose. It seems far more likely that it would be attributed to the nearest building belonging to that postcode. If this is the case then it gives us a way of tying these centroids to an actual building within each postcode area and that gives us something tangible to map. Can anybody suggest whether I'm onto something here?

Kind regards,

Adam

On Fri, 9 Nov 2018 at 13:27, David Woolley <[hidden email]> wrote:
If centroid has the plain (mathematical) meaning of the word, it will
only fall exactly on the building centre if there is only one building
in the postcode area.

In practice the building nearest the centroid might have its own
postcode, so you can't rely on the nearest building to the centroid
having that postcode.

There are, at least theoretically (e.g. a C shaped postcode) where the
centroid is in an adjoining postcode.  I imagine you would get this if
there was a cul-de-sac projecting into a crescent that was small enough
to have one post code.

On 09/11/18 13:12, Adam Snape wrote:
> Hi,
>
> I agree with not mapping the centroids but...
>
> Is it the case that the centroids are always placed on a building which
> falls under that postcode? If so, wouldn't it be okay to tag the
> building with the appropriate postcode?
>
> Another idea: Given that postcodes (with few exceptrions) apply to only
> one street, would it be acceptable to add the postcode tag to the street
> where there is only one centroid on the street?
>
> Kind regards,
>
> Adam
>
> On Fri, 9 Nov 2018 at 12:26, Tom Hughes <[hidden email]
> <mailto:[hidden email]>> wrote:
>
>     On 09/11/2018 11:44, David Woolley wrote:
>      > On 09/11/18 11:34, David Woolley wrote:
>      >> if you are only dealing with centroids, I think many have been
>     mapped
>      >> already,
>      >
>      > <https://taginfo.openstreetmap.org/search?q=uk_postcode_centroid>
>      > indicates that at least 2500 have been mapped.
>
>     Yes, but it's a stupid idea, so please don't...
>
>     Tom
>
>     --
>     Tom Hughes ([hidden email] <mailto:[hidden email]>)
>     http://compton.nu/
>
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Re: Postcodes

Robert Whittaker (OSM lists)
On Fri, 9 Nov 2018 at 17:08, Adam Snape <[hidden email]> wrote:
> My conclusion from this is that we can safely map postcodes to the building where their centroids are placed, perhaps avoiding doing so (or adding FIXMEs) on brand new developments.

There is one gotcha to that, which is that PO box addresses, and some
other large user "non-geographic" postcodes are geo-located in
Code-Point Open to the Royal Mail Delivery / Sorting office that
handles that postcode's mail. You don't want to be adding those
postcodes to the Royal Mail depot.

I've got a visualisation of the postcode centroids from Code-Point
open at https://osm.mathmos.net/addresses/pc-stats/ which can be
helpful for mapping. Once you get your eye in and get used to how
postcodes are assigned, you can often (though by no means always)
deduce from the centroid, the layout of buildings, and the locations
of the surrounding centroids, what set of houses/buildings belongs to
each postcode. The blog post at
http://sk53-osm.blogspot.com/2013/12/british-postcodes-on-openstreetmap.html
(already mentioned above) is a useful read in this respect.

Robert.

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Robert Whittaker

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Re: Postcodes

Philip Barnes


On 9 November 2018 17:51:40 GMT, "Robert Whittaker (OSM lists)" <[hidden email]> wrote:

>On Fri, 9 Nov 2018 at 17:08, Adam Snape <[hidden email]> wrote:
>> My conclusion from this is that we can safely map postcodes to the
>building where their centroids are placed, perhaps avoiding doing so
>(or adding FIXMEs) on brand new developments.
>
>There is one gotcha to that, which is that PO box addresses, and some
>other large user "non-geographic" postcodes are geo-located in
>Code-Point Open to the Royal Mail Delivery / Sorting office that
>handles that postcode's mail. You don't want to be adding those
>postcodes to the Royal Mail depot.

Very true, I would like £1 for every visitor to work has been via the Royal Mail Depot in Wellington.

Phil (trigpoint)
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: Postcodes

David Woolley
In reply to this post by Will Phillips
On 09/11/18 16:27, Will Phillips wrote:
> Sources such as Companies House don't validate their addresses, so this
> total will certainly include some proportion that are incorrect.

Most sources that do validate ask the user for the postcode an then to
select the address from the valid ones on the list.  I would say that
such sources were tainted.

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Re: Postcodes

Chris Hill-6
In reply to this post by Tom Hughes-3


On 09/11/2018 09:38, Tom Hughes wrote:
> On 09/11/2018 09:09, Phoenix830 wrote:
>
>> I want to add postcodes but I am aware of issues with this being
>> copyrighted material.
>
I maintain a GB postcode overlay, based on the Codepoint Open datasets.
This was last updated using the August 2018 data. I expect another
update shortly. You can see postcodes on a map I provide or use the
overlay tiles in your favourite editor. More details can be found here:

https://codepoint.raggedred.net/ .

I don't agree with either adding the postcode centroids themselves to
OSM, nor adding postcodes to roads. They are all about delivery points
not roads. If I find postcode centroids in OSM I routinely delete them.

There are roughly 1.7 million postcodes in GB (the Northern Ireland
postcodes are not released as opendata). I find that new postcodes are
created early in the development cycle of new building developments so a
new postcode exists often before buildings have even been started to be
built.

If you find any problems please let me know.

I also maintain a postcode layer based on the Office of National
Statistics OGL postcode data (ONSPD). There is currently a problem with
the way the tiles are generated, which I'm addressing. I believe
Codepoint Open and ONSPD are pretty much identical with the current
postcodes, but there is much more historical data in the ONSPD data.

--
cheers
Chris Hill (chillly)


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Re: Postcodes

ndrw6
On 09/11/2018 19:49, Chris Hill wrote:
> I maintain a GB postcode overlay, based on the Codepoint Open
> datasets. This was last updated using the August 2018 data. I expect
> another update shortly. You can see postcodes on a map I provide or
> use the overlay tiles in your favourite editor. More details can be
> found here:

This is a fantastic resource, thank you for making and maintaining it.
I've been using it for a couple of weeks and almost enjoyed tagging
postcodes! Sadly, osm.org doesn't seem to make use of addr:postcode tags
and maps.me is painfully slow when searching for them. But that's a bit
of a chicken and egg problem, I guess, as there are still not many
postcodes in the database.

I found it useful to highlight buildings and nodes tagged with
addr:postcode. Otherwise it is very easy to lose track of what building
have already been tagged. Below is a JOSM map paint style that does that
and displays the existing postcodes:

https://pastebin.com/raw/RxKNky3E


> If you find any problems please let me know.

Not really problems but:

- Overlapping labels can be difficult to read. Perhaps the script could
detect co-located postcodes and concatenate them.

- After the update some postcodes point to different buildings (likely
centroids have changed and snapping function produces a different
result). That could be a feature. It would be good to have a
simultaneous access to all versions of tiles.

> I also maintain a postcode layer based on the Office of National
> Statistics OGL postcode data (ONSPD). There is currently a problem
> with the way the tiles are generated, which I'm addressing. I believe
> Codepoint Open and ONSPD are pretty much identical with the current
> postcodes, but there is much more historical data in the ONSPD data.

It would be great to have e.g. a JOSM plugin combining address
information from open sources and making it easy (ideally with a single
click) to annotate postcodes and/or street names.

Many thanks,

ndrw6


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