[OSM-talk] All you've ever wanted to know about the french cadastre

[THEVENON Julien]

>>>> De : Simon Poole <simon at poole.ch>
>
>>>> Supposedly the cadastre includes street names and house numbers, however
>>>> of the 27 million buildings (plus 6 million wall=no) only a minuscule
>>>> number have further information attached, matter of fact there are more
>>>> nodes with addresses tagged in France than there are building outlines
>>>> with house numbers. Why this is the case, I don't know, but house
>>>> numbers etc. would be of far more immediate benefit to our data than
>>>> just building outlines.

Some people put the house number on a node located where there is the building entrace ( and sometimes forgot to tag the entrance)
Sometimes there are several house number on big buildings so house number is place on nodes instead of buildings.
Some people prefer to place the number where it is located physically, near the street when an house has a long alley
A lot of buildings outside cities does not have house number appearing in cadastre.
This kind of reason can explain what you are observing....
Cocerning building outlines it can be usefull for people performing study about urbanisation density etc so there is not one benefit related to one cateogry of data but benefits related to use.
Since we started to massively draw building outlines we also observe in France that people put much more POIs because this is very easier to add them when you have the buildings instead of just street because you know nuch more that your baker is just after 3rd building than 23meter after street corner...

The main interest of opendata is to allow unexpected usage so IMHO this is an error to decide in advance what has benefit or not for everyone

Cheers
Julien
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk/attachments/20120927/6ca2461a/attachment.html>