Relation:site

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Public-images-osm logo.svg site
Mf Relation.svg
Description
A site relation is used to group several objects together. Edit this description in the wiki page. Edit this description in the data item.
Useful combination
Wikidata
Status: in usePage for proposal

A site relation is used to group several man-made objects which cannot be adequately described by an area or a multipolygon. The group as a whole should have a common name and other common characteristics.

This relation is not to be used in cases where the element can be represented by one or more areas and neither linear ways nor nodes outside these areas would have to be included or excluded from within these areas. For example the tag amenity=school describes the perimeter of the school grounds, for schools with multiple sites the multipolygon relation should be used. For an university with sites scattered throughout the city, a multipolygon amenity=university with the buildings as role outer should be used.

The features should have a close geographic relationship, usually within the same town. For example do not use this relation to group all restaurants of a fast-food chain. Use a a combination of name=*/operator=*/network=*/brand=* to group loosely coupled and/or widely distributed features - relations are not categories!

See the proposal page for more context and examples.

How to Map

Create a relation and add type=site. In addition, the relation must have a main tag defining whatever feature the site relation describes. E.g. amenity=university, site=parking, power=plant, ...

To the characteristics all necessary tags are added:

Then the members are added without having to specify a role.

Members may include nodes or ways.

Problems

Sometimes other relations, especially multipolygon relations, have been added as members of a site relation. This can be difficult for database users to interpret, so it should be avoided where possible.

Site relations are typically not interpreted or used by database users such as map rendering or routing applications or any other software.

In many cases standard solutions, for example multipolygon relations, are a perfectly acceptable replacement.

See also