Since the GWR switched to including all buildings and not just those with a postal address a couple of years ago I’ve filtered out addresses of the form NN.N from the overall statistics (they are available in the files that contain “all” entries) as these are not “real” addresses, I’ve further refined that now by ignoring buildings with the category values 1010 and 1080 see GWR | Eidg. Gebäude- und Wohnungsregister
The changes and the update has reduced the overall count of relevant addresses in the GWR from 2’407’343 to 2’367’012 and the number of these missing in OSM from 732’394 to 698’960, the largest change probably being in Zürich which lost ~4’000 (Zürich is one of the municipalities that historically assigned any kind of building a regular house number, including for example the platform roofs at Altstetten station). The overall number of buildings (not addresses) in the GWR went up from 3’239’916 to 3’264’326 over the half year period since April.
I would note that it could be argued that the non-building buildings in the category 1010 should be included in the statistics, but there are only roughly 2’300 nation wide and even less with valid house numbers.
So the platform roofs at Bhf. Altstetten have their own housenumber? Wow, I didn’t know that…
In the specific case of Switzerland should we then always tag addr:housenumber on building=* polys or on entrances (barrier=gate/wicket_gate , entrance=*)? How do we keep track of phantom housenumbers like those you mentioned belonging to roofs etc.?
Per GWR house numbers are assigned to (building-)entrances in Switzerland so neither to the plot or the building.
However there are a couple of things to note:
not all cantons and municipality have all the necessary data (yet) in the GWR. For example the canton Ticino. In such cases the house number(s) are located on the building centroid.
there continue to be buildings that should have a full address assigned, but which only have a place/street value, typically farms.
and yes I could point out that swisstopo has managed to muddy the waters more than they already were, but lets ignore that.
There’s no real harm in having non-address house numbers. Matter of fact I have historically added them in Zürich because there are a fair number of cases where the ancillary buildings have a non-suffixed number (42) and the residential building is suffixed (42a) and it is then very confusing if you don’t map the non-suffixed number.
In any case lots of cantons and municipality didn’t assign house numbers to ancillary buildings before 2019 and they now use numbers with a dot in them (NN.N), with other words these are easily detectable.
I just spot checked Ticino and yes we still have the issue that the GWR has addresses on the building centroid and swisstopo uses AV data that has them correctly located (we discussed this on the mailing list back in April actually this was in May 2023 Re: [talk-ch] GWR Addressdata Update - talk-ch - openstreetmap.ch).
This is not a good state of affairs and maybe there should be consequences (hahaha)?
In any case I’ll probably add in the swisstopo entrance coordinates there is already some special casing for these cases but I was hoping that BfS and swisstopo would come to their senses and this could be dropped, no such luck.
replace the old count based coverage % (this goes back to the days before we actually matched addresses and was always just a rough estimate) with a coverage % based on actual matching.
various small bug fixes.
Note that the criteria we use to determine ancillary buildings are not perfect and there will be some slop. The shape files currently still contain all data except those with dots in the house number, that will be fixed as soon as I rerun the extract process.
One thing I might get around to this week is seeing if we can use the GWR building description attribute in any reasonable way (example addr:housename for buildings that don’t have a house number).
I’m interested in contributing by importing data from the GWR. While I’ve done my best to review available resources on the guidelines and best practices, I still have some questions. If anyone is available for a brief chat — ideally via video call with screen sharing — to walk me through some of the finer points, I’d appreciate the help.
I’ve made a start, and my initial changes are live here. Any feedback on these changes would also be welcome.
Thanks in advance to anyone who can provide some guidance.