Is it the right way to add the address and name of an object to the relation? Or should it be added to the outline of a building (which is part of the relation)?

See for example this relation:

I cannot find this building with Nominatim search via the name of the object (which is Markthalle VII) or the address (saved in the relation). Why? Is this a bug of Nominatim or bad tagging?

asked 06 Apr '15, 03:09

erik's gravatar image

accept rate: 9%

edited 06 Apr '15, 03:11

When using a type=building relation, you should still put the name and all other building-related tags – especially building=yes, but also the address – on the outline. This helps applications with no building:part support to correctly interpret the data. Note that this is different from the treatment of multipolygons, where tags should go to the relation instead of the outer way.

So in your example, you should move the tags from the relation to the outline. The building relation is not strictly necessary here (it is only required if there are ambiguities otherwise), so whether you keep it is a matter of personal preference.

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answered 06 Apr '15, 17:40

Tordanik's gravatar image

accept rate: 35%

I don't know if it makes any difference but instead of having the relation tagged as type=building I thought it should be tagged as type=multipolygon and building=yes

There is a multiple part building in my area tagged with type=multipolygon and building=yes with the addr:= in the relation which Nominatim finds.

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answered 06 Apr '15, 03:30

n76's gravatar image

accept rate: 17%


Multipolygon relations are not intended as a collection of objects (in this case, building parts). They simply represent an area, and are semantically identical to an area represented by a closed way. This is a common misunderstanding for some reason.

(06 Apr '15, 17:42) Tordanik

The samples near me are buildings with an inner courtyard so there are two ways one an "outer" and the other an "inner". I believe a multi-polygon is needed for that. Until looking at the example in the question I had not seen a relation used just to gather a number of building ways together.

(06 Apr '15, 18:29) n76

Ok, in that case a multipolygon relation is of course appropriate. However, this is a different situation than what we have here.

(06 Apr '15, 18:34) Tordanik
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question asked: 06 Apr '15, 03:09

question was seen: 2,892 times

last updated: 06 Apr '15, 18:35

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