smallest usable radius for location trigger

[nbi]

What's the smallest radius someone has specified and still obtained accurate and dependable results?

The default of 100 is too big for my flow, but comments in the forum suggest many people are using radii greater than 100 meters. For my flow 3 side-by-side buildings could easily fit within 100 meters (about the size of a US football field). My flow needs to be able to differentiate between these buildings so a much smaller radius is called for. Unfortunately this is not easy to test. Users of this flow will be outside approaching the buildings so GPS will be used. WiFi is not an option because I want the flow to resolve the location *before* the user enters the building. If anyone has experience with a radius much less than 100 meters please post your observations. Thanks for your help.

[MURTUMA]

The accuracy is dependant on your phone and things that usually affects location accuracy such as weather, blocking buildings or just plain luck. You have to test yourself at how small radius you still get dependable results.

Would there be any other ways to detect in which building you are? Wifi network maybe?

[nbi]

The accuracy is dependant on your phone and things that usually affects location accuracy such as weather, blocking buildings or just plain luck. You have to test yourself at how small radius you still get dependable results.

Would there be any other ways to detect in which building you are? Wifi network maybe?

No, because the whole point is to automate the presentation of information while the user is close to his/her destination but before actually entering the building.