Proposal:Remove man made=windmill from building scheme

From OpenStreetMap Wiki
Jump to navigation Jump to search
Tagging scheme for windmills and watermills
Proposal status: Draft (under way)
Proposed by: AntMadeira
Applies to: Applies to node area relation
Definition: Differentiates building=windmill from man_made=windmill and creates the new key windmill=* to refine the use of both elements.
Rendered as: picture
Draft started: 2025-01-27


Proposal

This proposal arises from the ambiguity between the tags building=windmill and man_made=windmill, whose wikis are almost indiscernible. The aim is to remove the association of the tag man_made=windmill to the building scheme, leaving building=windmill for those structures built as buildings to operate with the help of the wind (mostly to mill grains), and man_made=windmill to the devices which can operate independently or inside a building, thus clarifying the differences in their respective wikis. The same applies to building=watermill vs. man_made=watermill.

Rationale

As it happens today in OpenStreetMap, a windmill (normally mapped with the tag man_made=windmill) must be tagged with building=yes (or building=windmill) to be correctly rendered in the map. Thus, it doesn’t make sense to have two tags to map a building when you can have only one, which fits perfectly into the building=* scheme.

After consulting the community in the forum, there were some ideas to try and solve this ambiguity and contribute to more logical and specific tags, which fits in the already existing schemes of building and man_made.

The main idea is to map windmills and watermills has buildings when the structures were clearly constructed with that purpose, and leave devices or apparatus included in the man_made=* tag. These devices can exist independently from buildings (see examples below) or mapped as the device inside the building (if it still exists). To specify the use of the windmill, this can be further refined with the the new proposed keys windmill=* and watermill=*.

As discussed in the forum, due to the fact that the word "windmill" is used in many places around the world as synonymous of various structures/buildings/devices, and in order to take advantaged of the more structured and refined definition of man_made=windmill, it is also proposed to deprecate man_made=windpump in favor of man_made=windmill + windmill=water_pump.

Wind turbines for energy production (also called "windmills" in some places) have their own well established scheme and will not be included in this proposal.

Tagging

The following tables includes tags/keys which will be altered, created or deprecated.

Useful combinations are also presented.

Altered

tag description examples actual use
building=windmill This tag would be used only for buildings purposely built as windmills, i.e., to harness the power of wind by means of blades or sails to mill grains (mostly), drain water, saw wood or other purposes. The windmill=*, windmill:type=* and windmill:vanes=* keys can be added to better describe the structure and use of the building.
Moulin Moidrey.jpg
Windmill on Pico Island (21110913133).jpg
Goliath Poldermolen.jpg
More details at taginfo
man_made=windmill This tag should no longer make reference nor used to define buildings, since there's a more structured and appropriate tag for that. Instead, it should be used for devices with various purposes operated with wind energy. These can be external or internal devices. The present proposal suggests the transition of man_made=windpump tag to this one, deprecating the latter. The windmill=*, windmill:type=* and windmill:vanes=* keys can be added to better describe the structure and use of the device.

Pros:

  1. no longer use man_made=* tag to define buildings;
  2. the possibility to render windmills has buildings on the map, with their respective icon;
  3. reserve the more well known term "windmill" for those windmills which are not buildings and serve to pump water (currently man_made=windpump);
  4. introduce the key windmill=*, which can be expanded to refine the type of device (water pump, sawmill, grain grinder, tjasker, etc.).

Cons:

  1. For those windmill buildings already mapped using this tag, the tag building=windmill should be gradually added. For buildings in ruins, abandoned or disused, where the device is no longer present, this tag should be removed;
  2. The need to accommodate the migration of man_made=windpump to man_made=windmill (see below).
Goingarijp. (actm) 02.jpg
It Heidenskip - Tjasker 1.jpg
Interior Detail inside Keston Windmill (07).jpg
More details at taginfo
man_made=windpump Since this element is considered a windmill, mainly in the EUA and Australia, where they're more frequently used, this tag should be deprecated and migrated to man_made=windmill. It then can be further refined adding windmill=water_pump + windmill:type=lattice. A Maproulette challenge can be use to help in this task.
More details at taginfo
man_made=watermill This tag should no longer make reference nor used to define buildings, since there's a more structured and appropriate tag for that. Instead, it should be used for devices with various purposes operated with water energy, be it inside or outside buildings.
Braine-le-Château JPG02.jpg
Venn Mill - water wheel - geograph.org.uk - 3514851.jpg
More details at taginfo
windmill:type=* This key already exists and it's used to indicate the architectural/structural style, not the use. Its wiki should only be adapted and expanded to be used both with man_made=windmill and building=windmill and can have the following values (more can be added): post, tower, smock, tjasker, lattice, roundhouse, etc.
More details at taginfo
windmill:vanes=* This key already exists and it's used to indicate whether a windmill still has vanes (building or device). Its wiki should only be adapted and expanded to be used both with man_made=windmill and building=windmill and can have yes, no as values.

Created

tag description examples actual use
building=watermill This tag would be used only for buildings purposely built as watermills, i.e., to harness the power of water by means of wheels or other rotative devices to mill grains, fruits or to cut logs. To define its use, the proposed watermill=* key can be added.
Cordinger Mühle-05-2011.jpg
Moinho Adaúfe.jpg
More details at taginfo
windmill=* This tag is used to indicate the type of the windmill regarding its use, whether a building or a device. Possible values are windmill=water_pump, windmill=sawmill, windmill=grain_grinder, etc.
watermill=* Like with windmills, a watermill can be used to several purposes. Possible values are watermill=sawmill, watermill=grain_grinder, watermill=fruit_grinder, etc.

Deprecated

Additional tags

  • material=* - the most common construction material of the building
  • name=* - some historic buildings have their own name
  • start_date=* - the date when the element was created
  • craft=grinding_mill - indicates if the windmill is in operation, with people using it to grind cereals
  • craft=sawmill - indicates if the windmill is in operation, with people using it to cut wood into timber
  • ruins=yes - indicates if the building is in ruins
  • tourism=museum - indicates if the building originally built to be a windmill is presently a museum
  • tourism=guest_house - indicates if the building originally built to be a windmill is presently a guest house/chalet/etc.

Examples

example image tagging description

Rendering

The current icon for a windmill building would need to be attributed to building=windmill and not to man_made=windmill.

Windmill-16.svg

The icon for a watermill building could be something like this (used by HOT style):

Man made watermill.svg

Features/Pages affected

External discussions

The original discussion about this subject can be found at the community forum:

Comments

Please comment on the discussion page.

Retrieved from "https://wiki.openstreetmap.org/w/index.php?title=Proposal:Remove_man_made%3Dwindmill_from_building_scheme&oldid=2806178"