I’m sure this has been covered many times but I couldn’t find the discussions about it.
Is there a preferred (“correct”?) way to tag a business in a building? Should the business be tagged in the building as a way or tagged seperately as a node?
There seem to be different mappers which have one preference so certain areas are tagged as ways and then retagged as nodes and then possibly retagged as ways depending on the mapper.
Is this just down to personal preference? If some people are working their way round the map converting ways to nodes and others are converting nodes to ways, this seems like a waste of time.
This isn’t a criticism of either method - I’d just like to know whether there has been an agreement on a preferred way to do it.
you can do both, but a way (or other kind of area) is better because it conveys more information. You can add level to specify where it is (also possible with a node).
The important thing is you do not both for the same object, because this would mean two things instead of one thing
you can have several things also when you add them as polygons.
Yes that is true, but I (personally!) wouldn’t add them into the building polygon, because the building maybe has multiple levels or so. But yes, indoor areas are good too!
The best way to map businesses is if you manage to do map the area as a whole. This is such a precise kind of micromapping that it’s only really worth it if you’re this dedicated or you managed to find a floor plan of the building.
I mostly use nodes but mostly as a result of using Street Complete of adding shops.
@ezekielf’s method also is viable and also the most realistic one because some buildings (mostly) host only one business (maybe some auxiliary shop like a bakery or cafe) while others have multiple or aren’t even the main deal of the corresponding building.
What can be a bit complex is if a shop is spread around multiple floors of irregular sizes such as this McDonalds: It’s currently mapped as a site relation but this also is rather badly supported and not shown on Carto, for example. This might be one situation where a node is preferable even if the indoor areas exist.
It’s up to preference but I almost always mark businesses with nodes. I’ll mark the building as retail/commercial/etc and add the details that apply to the building then add the node in the center of the business (be it the whole building or part) and add all the business info there. Reason being is around where I am operators, owners, start dates, etc. can all be different [Edit: also many places the building may have a name different from its tenant] between the building and tenant even if there’s one tenant. It also makes it easier for me if a place subdivides in the future to just add a second node instead of detaching all the building info at that point.
Looking into versions, I also like seeing the history of business info / tenant info separate from “they got a new roof and now it’s red”
I hate to say it, but this information doesn’t belong on the building polygon, but on a separate polygon with the same shape as the building. There’s 2 simple reasons:
building=* is what I would consider a primary tag. If something has building=* set, then it is a building. amenity=*, shop=*, etc. are primary tags as well, and we should not have more than 1 primary tag on a node or way.
Buildings can have names. How is a data consumer supposed to know if this is the building’s name or the business’s? Yes, it will very likely belong to the business, but it’s not ambiguous.
It gets even worse when for example POI has a name and building also has a name. Then mapping both as single object in a tolerable way becomes basically impossible.
It is 100% definitely wrong when POI is not using entire building. Common when building has multiple POIs.
If you decide to map it in a bit broken way, one should not be surprised if POI name is treated as a building name or confused newbie in future will delete entire building because shop is vacant.
I would recommend mapping POI node and building area over mapping both as the same element. But it is also not horrifically wrong to map both as one element and it is commonly done.
Merging separately mapped POI and building seems clearly wrong to me, maybe except rare cases where building is POI by itself (for example ruins of a castle which are museum - with ruins as primary preserved and displayed object).
It is 100% definitely wrong when POI is not using entire building.
is it still 3% wrong if it occupies the whole building because it shouldn’t cover the walls, just the rooms?
(sorry, that’s maybe nitpicking)
Maybe a poi area should also cover the outdoor areas like greenery and parkings, if there are any? That would be straightforward but it becomes more difficult when there are 2 businesses, one on the ground floor and one at the upper floor. How would we map that they are in these floors and share the outdoor area of the plot?
The building tags are intended for the physical description of a building: for functions in the building (e.g. police station, church, townhall, museum) you should add additional tags like amenity=, tourism=, shop=* etc.
Both good points. I suppose you are correct that ideally a building and a business should be mapped as two separate objects. Taginfo tells me there are 3.2 million combinations of building=* + amenity=* and 1.2 million of building=* + shop=*. So it is a quite common practice to combine them. I can definitely get behind an initiative to move away from this practice though. I would then map businesses always as separate nodes.
I think the common understanding is that this tagging style is used when the building has no own name and no other properties refer to the building that are not clearly referring to the building (like building:levels refers clearly to it, and ref or start_date or wikidata do not). It is accepted as a shortcut, but as soon as you add more tags which would make the thing ambiguous you should separate them.
I’d rather things are mapped separately from the beginning. But people don’t know any better so you end up with thousands of buildings with just a company name
So: please separate them. Start with a node for the POI and if you have more details, expand it to its own polygon but not to the building
Its a preference - both ways work - IMHO there are a lot of disadvantages to put it on the building.
One of them is maintenance - Once the Business disappears you start sorting tags on the building - and randomly tags which describe the building itself (roof: building:levels, building:colour etc) disappear.
When you map it on a node the and business disappears you simply delete it (or put lifecycle tags on it)
Another disadvantage is for large buildings a routing issue. The destination for routing is always a “point” or “node” - When you tag stuff on a building its up to an algorithm to find the “right” node - Typically something like a Geometric Centroid of the buildings area. This node may be next to a completely different street than the one one would prefer to reach the business via.
Something like this - The Housenumber 308 destination would now be routed to the road at the top where the Navigation will tell you “You have reaches your destination”. Of course thats bullshit - but its the algorithm. Putting the POI on a node and moving it to the south within the building outline would fix this.
I’m glad I asked this question because it might completely change the way that I map - which I wasn’t really expecting.
It has always seemed easier to me to keep the business details with the building details and just update the business details as they changed (I can see this add problems where the building has a separate name to the business but this doesn’t seem very common and in this case the business could be added separately).
I think the danger with having businesses as nodes is that they aren’t tied to a specific area so it is much more difficult to see whether they are still there or not - it becomes much more important to add addresses to the nodes which can be difficult on a shopping street. This can be seen clearly in many shopping malls without outlined shop units which are very often completely out of date. And I think it is much more likely that the node will be deleted and a new one added when the business changes which potentially loses a lot of information.
I’m still not sure what I think the best solution is - but I’m much more aware of the issues now.
