[Talk-us] Addition of building footprints in selected U.S. and Canadian cities

Richard Weait richard at weait.com
Mon Apr 2 17:18:32 BST 2012

On Mon, Apr 2, 2012 at 11:46 AM, William Morris
<wboykinm at geosprocket.com> wrote:
> So here's something to mull over while we all wait for the license upgrade:
> http://dl.dropbox.com/u/23616645/Geosprocket_Share/umd_subset.osm
> That's an extract of the UVM-SAL building footprints I'd like to
> import for swathes of MD and PA. My workflow for killing existing
> feature conflicts actually went best without involving ESRI at all:
> 1.) In QGIS, Set up 0.2-degree import grid over new building coverage areas
> 2.) Pull down one grid cell worth of OSM data using the QGIS OSM plugin
> 3.) Add building footprint .shp, select all footprints that intersect
> OSM lines or polygons
> 4.) Switch selection, save as new .shp
> 5.) Run ogr2osm.py on new .shp (Special thanks to Andrew Guertin for
> running me through that process)
> 6.) Open new .osm file in JOSM, add building tags, upload.
> 7.) Repeat for next import grid cell
> Tedious, but it'll get the job done. And a reminder: I do not intend
> to add any building footprint that conflicts with an existing feature,
> adhering to the OSM preference for user-added features over imports.
> Now soliciting thoughts, roadblocks, expressions of ennui, etc.
> Thanks!
> -Bill Morris

My objection is a generic one and one that has been heard before on
this channel.  To be clear, I do not wish to criticise Bill; he
appears to be following the bulk edit guidelines and he is engaging in
the discussions here.  That's fantastic.  Bill, welcome to the

I think imports (taking a large number of objects from an external
source and placing them in OSM all at once) is bad for the community.
Most of you have heard me say this before.  I still have no hard
evidence to prove it.  There is also no hard counter-evidence.  At
best, imported data will be unmaintained.  I glibly offer most TIGER
ways as evidence.

I ask you to suspend disbelief for a moment, and presume that imports
are generally bad, and presume that adding new mappers is generally

Can we try something new?  Can we use this building data as motivation
to get new mappers in those areas so that specific mappers will have a
stronger connection to the data in specific areas?

Something like this:
- Let's set a smaller grid. Something like a large suburban arterial
block, say 1.5km / 1 mi square.
- If you want to import the buildings in one grid square, you have to
find a new mapper in that area, and they have to do an on the ground
survey of some part of that area.
- You can only do so in areas that are no more than four grid squares
from your home location (or work location).

This is a cross between "adding game-features to OSM", "banning
imports" and "having users adopt part of the map".  :-)

This could be really beneficial to a new mapper.  They could survey
the local fire station, police station, hospital and schools, and
perhaps the businesses on the main street, and a few local shopping
malls.  They get all of those business names, and they'll be
completely up to date.  They'll add them to the map, and they don't
have to trace as many building outlines, because they have the
external source available.

What I hope this will encourage is:
- new mappers in those areas
- who will do new foot surveys of interesting things
- and will feel attached to the data
- and keep it up to date over time.

And, if the new mapper understands that the building data for their
area is a "reward", they are unlikely to be frustrated or discouraged
by it if some buildings end up in the wrong place.  the new mapper
will just fix them.  And carry on mapping.

I know that what I suggest is much harder than simply importing the
data from one or two accounts.  I suggest that the benefit of finding
and encouraging new mappers in your area is much greater than just
having new building outlines in your area.

Now the Negative Army will jump in and say, "That's too hard.", "That
will never work.", "I want buildings now."

You can take leadership on this.  Are you the only active mapper in
your city or region, or one of only a few?  Do this.  Be a leader.
Grow the community and then you won't be able to keep up with the
growth of the map.  Build new contributors.  (And host local OSM

Thanks for letting me hijack your thread, Bill.  :-)

Best regards,

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