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Duplex and Multiplex

Hello, I'm new to OpenStreetMaps, since the G...le Maps is super big in my area. I have only created a few edits so far, but before I get ahead of my self I wanted to make sure I'm adding buildings correctly. . My neighborhood is full of Duplexes but we do not have normal unit/apartment numbers we have a house address. So instead of 1912A and 1912B we have just 1912 and the neighbor has 1913. Do I use the house address and draw to separate squares for each or do I draw two separate squares and select multi family and add the house=addr??? Super confusing because of the area I'm in.

asked 23 Oct '21, 07:13

trwidick's gravatar image

accept rate: 0%

A duplex is two homes sharing a wall. Normally look identical, but some times not. In other words its two apartments only. And our neighborhood uses house numbers instead of apartment. So is this correct. I made two boxes, and made them houses with the middle wall going down the split. I can do this for my whole community if need be. alt text

I Left one with out boxes so you could see the the style of building.

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answered 23 Oct '21, 20:16

trwidick's gravatar image

accept rate: 0%

edited 23 Oct '21, 20:17


Yes, in the UK where terraced houses (townhouses) are much more common these are called semi-detached. OSM started in London so it tends to follow British English. Splitting the building into two and tagging as building=house as you seem to have done in the screenshot is a fairly common way of mapping these and allows independent mapping of the two addresses.

(23 Oct '21, 20:38) InsertUser

As an addendum if you have quite a few of these to draw and are willing to install some software on your computer JOSM has a few plugins that can make drawing the ways really quick. My personal preference is to use the BuildingsTools or mapathoner plugins for drawing the outlines and the Terracer tool for splitting them up.

(23 Oct '21, 20:46) InsertUser

I kept doing that but I changed the type of building=Semidetached_hosue

(23 Oct '21, 20:52) trwidick

I'm not clear what you refer to as duplex. Side by side or over and under? Anyway, just put the address to the complete building that has the number and tag it as building=house, building=semidetached_house, building=apartments or whatever seems most appropriate.

If two buildings with different numbers are attached make sure they share a wall (two nodes) when mapping them.

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answered 23 Oct '21, 12:14

TZorn's gravatar image

accept rate: 15%

Normal "side by side" duplexes are normally building=semidetached_houses.

If by multiplex you mean "townhouse style" houses like a normal duplex but with additional houses in the middle of the row then the building as a whole may be tagged as building=terrace.

The best summary of the various options is probably this page on the wiki.

Either of the above can alternately be mapped with a split at the dividing walls and each individual dwelling tagged as building=house. This would allow the individual houses to be given their own addresses. If this is not feasible or would require too much guesswork then multiple address nodes at roughly the correct locations within the overall building is also acceptable (and preferred in some places with government opendata), some people prefer to put them on the front doors in which case they would get building=entrance too.

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answered 23 Oct '21, 13:31

InsertUser's gravatar image

accept rate: 19%

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question asked: 23 Oct '21, 07:13

question was seen: 1,021 times

last updated: 23 Oct '21, 20:52

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum