Talk:Buildings/Archive 1

Joined buildings

Resolved: The convention is to share nodes for common walls. Just one building is a good first pass drawing.

If there are 2 or more separate buildings that are like "stuck together"(the one being built right next to the other without any air separating them), should I add it as one building(?), or two with very close borders? By default I would add it as 2, but I'm interested in opinions Logictheo 00:19, 22 August 2008 (UTC)

I've managed to understand how to do this. It was a practical issue on how I could do it in josm. Logictheo 13:07, 15 September 2008 (UTC)

How did you do it? — Sam Wilson ( Talk • Contribs ) … 04:12, 3 October 2008 (UTC)

JOSM's new extrude tool followed by splitting the extruded object at the right two points and extending both of the resultant ways to be loops again does the trick for me. --achadwick 14:14, 12 January 2009 (UTC)

Hmm. I can extrude one side of a building like that, but I still get a message from the validator about overlapping ways. It's just 'info' level, so I suppose I can ignore it, but is there any way to deal with this that the validator actually likes? I thought the right way to do this would be to have the two buildings share one side, but I can't figure out how JOSM would do it, and the validator might choke even worse on that. grendel|khan 16:05, 26 February 2009 (UTC)

The Terracer plugin: JOSM/Plugins/Terracer may also be useful, or at least it confirms that shared walls mapped as overlapping ways (with shared nodes) is a widely used approach. When mapping joined up buildings manually, the unglue and merge tools come in very handy (often in short succession) -- Harry Wood 01:32, 3 December 2010 (UTC)

House numbering

Resolved: addr=:* tags have established themselves after this was asked.

I added the house numbering proposals. Are there any more proposals dealing with this ? Nochmaltobi 20:04, 1 November 2008 (UTC)

If there were, they don't seem to have any support. Somebody could tell us in English how the Japanese do addressing, though. Alv 07:29, 8 February 2012 (UTC)

Canopies

Resolved: Add covered=* for the feature below the canopy, and elevate the building overhang.

Some notable buildings have huge canopies that I feel need to be considered when one starts to add the surrounding pedestrian areas in detail. So far for few such I've drawn a separate area for the canopy and have used building=canopy + layer=1. Yet this proves to be suboptimal, since for example a railway station the rails and platforms get hidden... Would it be good to have a separate (rendered) tag for canopies? That would allow for a more consistent description of some mainly pedestrian areas. Outdoors - under the canopy - inside the railway station. Alv 16:27, 15 December 2008 (UTC)

City Buildings

Resolved: Try to find the actual location of the wall, not some imaginary point in the middle of the road.

How should one form buildings which abut the surrounding streets? E.g. when looking at [1], most of the mapped buildings can be touched when standing on the sidewalk between them and the actual lane. Currently they seem to be drawn to match the Yahoo! images, but this leads to IMHO ugly "white" space between the buildings and the street when zooming in. On the other hand, reusing the street's nodes for the building, also leads to [strange overlappings in mapnik] (see Piaristengasse/Piaristengymnasium). Please advise! --David Schmitt 17:01, 28 December 2008 (UTC)

Positioning the walls where they are is correct. Reusing the road nodes would mean that the buildings touch each other when in reality there's a road in between. If the road elements were eventually drawn as areas and if there was an agreed way, such highest zoom maps could use those to draw the roads at their exact width. Using JOSM you can adjust them so that the distance between the walls on opposing sides of the streets is realistic or accurate if you measured it - but visual estimation of the width of the road leads to quite good results (say, "here's two lanes of about 2.5 meters each, parking spaces of 5 meters and two sidewalks of 3 meters each") Alv 07:33, 29 December 2008 (UTC)

Yes. We used to do it the other way in Oxford for college buildings - very unmaintainable. Admittedly the whitespace and overlap can be ugly sometimes, but that's a renderer issue, and you shouldn't attempt to fix it in the data.

It's a bit less true of landuse areas because those are slightly interpretation-based anyway. I prefer to not abut them to roads and paths for maintainability. --achadwick 14:19, 12 January 2009 (UTC)

I agree with the idea that buildings should not touch the roads in OSM. We mark the center-lines of roads and not the actual area of the road so making buildings touch these center-lines is wrong. --Seav 10:47, 14 January 2009 (UTC)

Start adding sidewalks - their position will indicate the width of the road at high zoom, and make the buildings appear closer to the highways. Ojw 10:17, 2 August 2009 (UTC)

Estimated height

Resolved: Most people use height=* even for estimates - mappers seldom have access to accurate data anyway.

Why not adding a tag estimated_height=integer in order to be compliant with a mapnik feature, which allows to draw pseudo-3D representations of the buildings ?

See The mapnik feature, and This link for a rendered example

Because we already have est_width=* and should therefore call that tag est_height=*. --Tordanik 15:06, 31 May 2009 (UTC)

just call it height= -- everything in OSM is estimated and can be improved further if someone finds better information - you don't need to send renderers searching through a whole slew of different tags just to get the height. Ojw 10:19, 2 August 2009 (UTC)

IMO if you know it's a very rough guess, one could add a note=* or, say, source:height=rough estimate. Alv 07:29, 8 February 2012 (UTC)

House Numbering II

Resolved: Only the french and russian pages still have a link to the less used relation.

Mentioning two address-schemes was good, when it couldn't be determined which one will be used more frequently. Now the Karlsruhe Schema by far outnumbers Relations/Proposed/Postal Addresses, so I removed the later for clarity. Relations/Proposed/Postal Addresses seems to be abandoned anyway.

I also adjusted the de-translation, but my frensh, japanese and russian language-skills are...well...limited, so they have be done by somebody else. Nochmaltobi 15:46, 10 January 2010 (UTC)

Node or Area?

Resolved: Building nodes are an acceptable first pass mapping attempt, but will eventually turn to areas.

The table at building=* defines most values as applying to areas (closed ways) only. Is this just an oversight or has it been deemed undesirable to map a building as a single node?

A typical new residential house in my area has up to 16 or more corners, partially obstructed by eaves. I am mapping most such buildings as a single building=house node, with address tags when known. If someone doesn't approve of this, they are welcome to come and trace the other 15 corners. :-)

Btw, some houses happened to be under construction with bare foundations visible in my high-resolution aerial imagery sources (February 2006 USGS Ortho or, in some areas, ~2009 Bing). In these cases I generally trace the full outline.

--T99 21:15, 24 December 2011 (UTC)

Sounds very reasonable. You add a node and the address and if someone wants to turn them into areas then they can do so. However... if you feel like doing simplified areas with less corners that would also be good. It is easier to add corners to an existing area than to a node. Personally I would encourage you to do a rough outline. PeterIto 21:32, 24 December 2011 (UTC)