Near were I live there is an industrial estate part of which has retail units on it. The mapping of this area had the buildings mapped as three areas, but with no details. Two of the actual building are made up of several units each one housing a shop. So, after visiting the area to confirm the shops, I went in and split the single buildings up into units. I then added the “addr”, “name”, and “shop” tags to each one to detail them. On OpenStreetMap this shows up as each building and you can see what is there, i.e. you can see Pets At Home next to Halfords etc.
Near where I work there is another retail park already mapped. Now again this one is made up of single building containing multiple units (and hence shops). From OpenStreetMap I could see the buildings but only one of the shops. However when I came to edit it I saw that in fact all shops were there but as nodes.
Which is the correct, recognised, method in this case? Applying the details to areas or nodes?
Personally I think building area tags are better as they are all visible on OpenStreetMap, but I want to get it right!
So there is one building with several shops? In this case there should be only one building in OSM. It is vaild to map the shops as areas without building=*.
Yes, it is best to map shops etc as areas where possible. As this gives you more information, ie you can see how big the shop is, and the area it covers.
Obviously this is more work than just mapping them as nodes, and it requires suitable aerial imagery etc. So many shops are just mapped as nodes, especially those mapped before aerial imagery was available. This is not ‘incorrect’, but mapping them as areas would be improving the map, so is worth doing.
As for tagging, there is some debate as to the best way to map a building split into multiple shops.
You can map the outline of the whole building, then tag that as building=yes, then map the individual shops as areas within this (without building tags).
Or you can map an area for each shop (joined to each other where they are connected), with each tagged as building=yes, plus the shop tags etc. As they are joined to each other, it makes clear they are all parts of one building.
I usually prefer the second of these methods.
The exception would be a shopping mall/shopping centre. As the shopping centre usually contains corridors and other facilities in between the shops. So it makes sense to that as shop=mall plus building=yes. Then map individual shops within that, as areas if possible, or just as nodes.
