This is not exactly new question - I found few related posts, but they didn’t give me the answer I am looking for.
I am actively working on mapping Crawley, UK and there are few commercial buildings with the residential townhouses above them with the entrances on the second level - for example OpenStreetMap or OpenStreetMap
The townhouses got addresses different from the commercial units below, so I mapped the townhouses as a separate buildings with layer=1 (the commercial building below got layer=0). I know it is not exactly the standard way to use layer tag, but this approach seems to be very clear and intuitive.
Recently, another user changed the “townhouse” above to “building part” effectively removing the addresses from the map (as far as I understand buildings parts are not supposed to have different addresses), because maproulette ignored layer tag and showed those two buildings and intersecting. So the user resolve this conflict this way.
I did my best to find buildings with same layout in other parts of the UK to follow the scheme, but could not.
I do like approach I follow now, but I would like to know if anybody know a better approach to handle this situation?
I’m sorry for your experience with Maproulette, unfortunately not checking mapping and not communicating with the original mapper is typical for Maproulette users.
Would you be able to link to or upload an image of these buildings? I’m curious whether these are best described as physically two distinct buildings, or could it be thought of as one building with commercial use on one level and residential uses above? (Unfortunately OSM doesn’t seem to have a good way to tag multi-use buildings like that.)
Are the residential entrances at the back, from the mapped footway? Maybe an option could be to map the residential entrances and tag the address there?
Could they be mapped as building=apartments, with the address of the residential part on the building area, and the address of the commercial units on shop=* nodes within the building area? That’s how I would map it but I’m not familiar with UK mapping practices.
I’ve certainly lived in flats like that before (in fact even one where the ground floor shop was in a different post code to the 1st floor flat! As the latter had its entrance steps round the side of the building in a different street).
One way I have mapped this kind of thing is just to draw the building itself and mark it as residential, and to add a node for the shop. It’s not as elegant as your method, as it doesn’t make the ‘layer’ distinction.
Unfortunately, I don’t have the pics of the building, but yes, the entrances are at the back accessible from the private footpath at the second level (i.e. first floor in the UK notation)
Ok, going by pictures found on DuckDuckGo for “Tilgate Parade Crawley” (e.g. 1, 2, 3, 4), personally I would map this as one building, with residential addresses on entrance=home nodes (see Key:entrance - OpenStreetMap Wiki), and if you want to tag the residential part, building:part=residential, building:min_level=1 (see Key:building:min_level - OpenStreetMap Wiki).
As far as I understand, the entrance node is expected to be placed on the building way (i.e. outline), and to map those addresses as entrances would require separate polygons, because in case of a single building, the entrance will be in the middle of it (the actual entrances projections are in a middle of the building footprint).
I think if there is no huge objection to my approach, I would stick to it now. Thanks everyone for advice
Cheers!
If it’s one cohesive building then it should be mapped as one building. Mapping it as multiple buildings is incorrect. (Consider this huge objection to your approach)
A building having multiple different addresses is nothing unusual. The addresses should simply be added as address nodes and not tagged on the building itself.
Apartment buildings can also have shops on the ground floor, that’s perfectly fine.
It usually is, but does not necessarily have to be.
that is not a blocker or hard rule - though if a single building has multiple addresses I would use address nodes instead
if and only if entrance is located there (it is typical, but not always happening - rarely entrance is from the middle of tunnel=building_passage or covered building part and therefore within the building)
Yes, while it is not always clear which is a building and which a part, if you believe that it is a single building, it should not be split into 2 buildings (the typical situation I see mostly is actually the contrary: many buildings unified into a single building in OSM). But: you can always split a building into several building:parts, and you can add building:use to building:part so it is not a showstopper.
+1, Buildings often aren’t necessarily correlated with addresses, several buildings can have the same housenumber (when the number is referring to the plot and not to the building) or several housenumbers can be located inside the same building.
Generally, while apartment buildings can have shops on the ground floor (or other floors), these buildings are different from pure residential buildings (there are by the way also such buildings where the shops have been repurposed and are now used as apartments as well), and I believe we should be able to distinguish them (other than just placing a node with shop tags in the outline)
