Came across an example of monthly serviced apartments in Chiang Mai, that was initially tagged as tourism=guest_house and recently changed to building=residential + guest_house=guest_house, in both case tags does not seem to fit.
In this specific case, it seems the entire building offer serviced apartments, however I am aware of buildings that accommodates floors to commercial, hotel, office and serviced apartments sections.
Some possibly relevant tags:
building=apartments + building:use=apartments
tourism=apartments
landuse=residential + residential=apartments
What is the best tagging approach for serviced apartments ?
For my understanding, a serviced apartment has to be:
a large building
provide long-term rental
provide a hotel-style service such as breakfast
The guest house might be inappropriate since the serviced apartments building is too large to be defined as a guest house.
I think we should divide the problem into 3 parts.
For a land area, landuse=residential + residential=apartments is clearly appropriate.
For a building, building=apartments is clearly appropriate.
The problem is only for a service-related tag. I think any tourism=* is supposed to be used for short term rental, such as a holiday or vacation. What we need might be a new service-related tag, since there are so many different types of residential service. For example, there are some condos in Bangkok provide a service like a 5-star hotel to private owners. They may also need some service-related tag too.
By the way, some serviced apartments may provide short-term (less than a month) rentals. In this case, they have to register to an authority as a hotel, according to the Hotel Act. For them, a tourism=hotel should be appropriate.
(FYI, If we look at Google Maps, we can see many serviced apartments tagged as hotels.)
For a mixed-use building, building=commercial with a building:part=* should be fine.