OpenStreetMap
I have put the following item on the Irish mailing list. I will put it here to widen out the inputs. If you have some time, and some experience of adding this landuse. Rather than repeat all my concerns I will simply post visual some examples of the issues I am talking about here.
Example of an urban landuse=residential which is gigantic.
Example of a landuse=residential interpreted at running along a roadway to incorporate ribbon(roadside) developments. This landuse connects a huge number of disconnected places.
Example of a landuse=residential residential where the landuse is trimmed back from the public highway and walkway, and doesn’t extend beyond the collective block of properties.
Discussion
Comment from alan_gr on 5 April 2022 at 08:13
I haven’t mapped a lot of this myself so my comments probably have limited value, but based on my observations of how this tag is used in Ireland and Spain this would be my reaction to your examples:
1 - I don’t think the size of this area is a problem in itself - I would be OK with a large polygon if the whole area is genuinely residential. But I feel that is not the case here, as it contains a lot of non-residential landuse (hospitals, the Jesuit centre, sports grounds that are used by people beyond the immediate area). This feels like a first step at mapping, aimed at conveying the general idea “this is a built-up area, not countryside”, that could have been refined over time but wasn’t.
2 - I have never seen this before and I don’t think it is consistent with normal use of this tag. First impression is that it has been created by someone unfamiliar with the use of multipolygons, resulting in meaningless strips of land tagged as residential. Changing to a multipolygon would be technically better, but I don’t think I would be happy with it even then, as there seems to be no reason to connect this specific set of houses. The information “there are scattered individual houses here” could better be conveyed, I think, by mapping building=house (presumably if the available imagery allows mapping of residential plots at this level of detail, it would also allow mapping of individual buildings). Perhaps adding landuse=residential to the surrounding private gardens if someone really wants to be precise.
3 - I’d view this as OK but perhaps unnecessarily complicated. For me it is fine to include highway=residential and small pieces of grass/park within residential landuse, so if I was mapping a new development myself I would map a simpler outline. But I wouldn’t change it if I found it already mapped with this style, provided the excluded parts have an identified landuse as they do here (implied in the case of highway=, explicit in the case of landuse=grass).
Comment from Smef09 on 5 April 2022 at 09:11
I am confused about this tag, prolly because of the many ways people use it to mean different things. I assume it means that the area is not agriculture or natural, and humans live in it.
In big cities I often want to add the tag for natural woods. Is it wrong to add this without making a relation or a gap in the residential?
Comment from b-unicycling on 5 April 2022 at 13:54
I agree with not mapping scattered houses as one landuse=residential (to show it is one village? or why?), especially when it goes over landuse=farmland (which might not be mapped)
I’m not sure if public lawns (landuse=grass) should be excluded from the residential area, in a way, they are an important amenity of the residential area, but nobody is technically living on them (unless a homeless person puts a tent up).
All in all, I think we could do better. ;-)
Comment from kucai on 5 April 2022 at 22:55
Some people just tag landuse residential just so that it is rendered as the size/outline of the town/city at lower zoom level.
Comment from Xvtn on 12 April 2022 at 15:48
Personally when in doubt, I imagine myself standing in the spot in question, looking around me, and asking the question “Am I in a residential area?” That leads me to the following conclusions:
Yes, include in landuse=residential
Not a residential area
That being said, I think the strategy that alangr mentions where you map out rough large areas initially and replace/refine them later is a pretty good one. “Breadth-first” rather than depth-first improvements so to speak.
Comment from Xvtn on 12 April 2022 at 15:50
Wow, even H2 subheadings are rendered huge here…