I am quite new to OSM but I think I got the basic understanding. One thing that is still unclear is the difference between house numbers (add:tag) for a building and an adress point.
After I creating a building including setting a propper add tag, why do I have to create an additional point and have to enter all adress details again to get the house number shown? That really looks like unneccessary double work for me.
Is there anyone who can give me an explaination or a better way for that?
To see the address on the main OSM map, you just have to add the tags “addr:housenumber” and “addr:street” either on a polygon or on a node. You don’t have to create both but many people add the address on the building polygon and later, someone else is adding a POI (e.g. a shop) with the same address again. At the moment, it is not so a problem if the address is repeated. What is important is that the house number is correct and the “addr:street” corresponds exactly to the street name (the tag “name” of the nearest “highway” way). All other addr tags like “addr:city”, “addr:country” etc are optionnal and rather useless. The postcode tag might be necessary if it’s not specified at a higher level (an admin boundary)
Thanks for the answers.
Yes, that is exactly what I thought at the beginning. But OSM really seems to need the double work for whatever reason. I also think this might cause some trouble later if some app finds the double tags.
However: Here is one example: Two buildings: both with the polygons tagged, one with an additional address point (with the number on the map (mapnik) ). And this is not the first time I found this behaviour.
Okay. LordOfMaps is right : your object has the address AND a name. In this case, the rendering rules for the slippy map has to either print the address or print the name or print both. The current main map (using Mapnik) has decided to show only the name when both tags are present. This is not necessarily a bug but might be a design choice (we cannot show all data in OSM).
As an alternative, you might check that in some parts of the OSM world, the address is tagged on a node attached to the building entrance (or nearly, at least the facade). See here for example : http://www.openstreetmap.org/#map=19/48.85279/2.33834 in Paris or there http://www.openstreetmap.org/#map=19/52.51728/13.38802 in Berlin.