If you use building=house, etc for residential properties then non-residences stand out more, which I think looks quite good. I am guessing it is intentional as the rule is in the style file; ['residential','house','garage','garages','detached','terrace','apartments'][1] are rendered without the line around them, and other buildings with the line (there seem to be special rules for stations, supermarkets, places of worship and airport terminals). See for example [here][2] [1]: http://svn.openstreetmap.org/applications/rendering/mapnik/inc/layer-buildings.xml.inchttp://svn.openstreetmap.org/applications/rendering/mapnik/inc/layer-buildings.xml.inc [2]: http://osm.org/go/0EHmTf5k

If you use building=house, etc for residential properties then non-residences stand out more, which I think looks quite good. I am guessing it is intentional as the rule is in the style file; ['residential','house','garage','garages','detached','terrace','apartments'][1] are rendered without the line around them, and other buildings with the line (there seem to be special rules for stations, supermarkets, places of worship and airport terminals). [1]: http://svn.openstreetmap.org/applications/rendering/mapnik/inc/layer-buildings.xml.inc