|landuse = residential|
|Predominantly houses or apartment buildings.|
|Used on these elements|
|Status: In use|
|Tools for this tag|
An area of land dedicated to, or having predominantly residential buildings such as houses or apartment buildings.
If there is a small (one company/property) area of commercial (or similar) landuse within an otherwise residential area, you can still decide to use landuse=residential for the outline of the whole larger area as a preliminary solution. You could later draw a separate area tagged with landuse=commercial for that commercial establishment.
The landuse tag is mostly used for larger areas and not at parcel granularity; as described above, a single shop in a residential area might not always warrant an extra "commercial" landuse.
Of course, if the change in landuse is significant, then it makes sense to map it. Significance can either come from size - if there is a whole shopping mall in a residential area, one would probably map this separately - but even something small can be relevant. This is the mapper's decision. If you want to make a hole for another landuse inside a residential area, you can use a multipolygon relation for that (but usually it will not be needed, if you map at a detailed level you will not include the streets so that the commercial landuse will always be at the edge of the landuse).
Separation from roads
It is disputed whether a (small) road leading through a residential area should be included in the landuse, but generally (public) roads are a different landuse than private land. Some mappers split residential areas into blocks that do not contain any streets; others restrict such splitting to major thoroughfares, and still others draw one big residential area around a whole town (which is considered preliminary by the majority of mappers).
If you choose to let a landuse area end at a road, you have a choice of either re-using the nodes of the way representing the road, or drawing the boundary using new nodes next to the road. Both methods have their advantages and disadvantages, and neither is clearly "wrong" as long as highway landuse is not mapped. Still it is suggested to let the residential landuse end at the actual border and not extend it to the centre of the road for various reasons, e.g. to simplify later refinements (highway landuse), not to locate things on the public land (road) in adjacent landuses and to avoid inexperienced mappers accidentally connecting roads to landuses rather than other roads.
If you had access to land parcel data, you'd probably draw the ways with landuse=residential along the parcel edges, which are (mostly anyway) some distance away from the road centerline, i.e. behind the sidewalk. Draw accordingly or discuss at Key:landuse discussion page.
Named residential areas
Most landuse=residential objects in OSM are nameless, simply indicating general areas used for residences. However, housing estates and other specific residential areas are also often given their own landuse=residential area plus the correct name=*. For housing estates you might also like to use operator=* to indicate who runs the estate (e.g. the local government).
There are also place tags such as place=neighbourhood or place=suburb. These can be used on an area, perhaps the same area as landuse=residential, but if the boundary of the area corresponding to the name is not clearly defined (as is often the case) you can consider putting such place tags on a separate node, although the area has clearly advantages even if only approximative.