[HOT] Houses or buildings with no roof in W Africa mapping

Nick Allen nick.allen.54 at gmail.com
Sat Sep 13 07:43:23 UTC 2014


Blake,

They could be both. When I asked the question a few months ago 
concerning similar structures elsewhere in Africa I was told that it can 
take a while for something to be built & finished, but it can also be a 
case of something has become disused & the roof removed. In either case, 
it would be a relatively quick job for someone to clean it up and add a 
roof.

Something to consider - since the satellite imagery was taken the 
structure could have changed - now be complete & with residents. In some 
areas corrugated iron is available & a roof could be added in a few hours.

The other option is something like a pig sty - a small building with a 
roof for the animal to shelter in with a compound or compounds attached 
to it - pigs, goats, etc..

I can't see for sure what that particular image is showing  - probably 
the animal compound but it could just as easily be the residence in 
decay or slow construction.

The outlines we are tracing today could be unchanged on the map for many 
months / years. I try to make sure they will appear in the data in one 
format or another because at least someone using just the map data can 
look at it and say "There's some kind of building there" & perhaps 
another say "That's John's farm, it's gone now but the road still goes 
through there" - you need the local knowledge that we just can't possess.

Acceptable options to me all involve the structure being traced and 
appear in https://wiki.openstreetmap.org/wiki/Key:building . Whatever it 
is, it's construction includes barrier=wall which is also a valid 
option. I have no wish to offend someone who is probably a better mapper 
than me, so I try not to alter tags if they appear in the wiki, but I 
will probably do so if they don't render in Mapnik or Humanitarian style 
renderings.

If it was me doing the tracing I would keep it simple;
barrier=wall
or
building=yes

Hope this helps

Regards

Nick
(Tallguy)

On 13/09/14 05:44, Blake Girardot wrote:
> Hi,
>
> New user supersonic3974 asked this question in irc last night but 
> didn't get a reply:
>
> [22:45] <supersonic3974> Hey, quick question.  What are these things 
> that look like buildings under construction?  They seem to be 
> everywhere.  Here's an example: http://imgur.com/ccS03xv
>
> I have that same question coincidentally enough.
>
> They look like buildings with no roof.
>
> Are they buildings under construction or structures that lost their roof?
>
> My guess is we wouldn't outline them since they probably are not 
> inhabited, but I don't know for sure.
>
> I'll make sure he gets an answer if someone replies here.
>
> Cheers,
> Blake
>
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-- 

Nick

Volunteer 'Tallguy' for 
https://wiki.openstreetmap.org/wiki/Humanitarian_OSM_Team

http://www.openstreetmap.org/user/Tallguy

Treasurer, website & Bonus Ball admin for 
http://www.6thswanleyscouts.org.uk/ (treasurer at 6thswanleyscouts.org.uk 
<mailto:treasurer at 6thswanleyscouts.org.uk>)

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