Some have also discussed whether `addr:building=` should be used. Perhaps it can be used in subbuildings ie `addr:building=1` + `addr:unit=1A` to show Tower 1A and 1B belongs to the same buildings. In this case, they are the same for one house, so not especially needed yet.
Another question is whether "Tower" or "House" should be included. For `ref=`, numbers are enough for blocks, and "Tower" is usually coded as "T1". But to generate an address with `addr:unit=`, it is unclear how it should be. 