In X-plane, the default ENBR (Bergen Lufthaven Flesland) was listed as '3D' featured airport - however there were no buildings there! In LIttle Navmap it showed as 5 stars which is not good (for me). I then downloaded a pretty good version of it from the x-plane org, it now shows as a 'helipad' featured airport and now only has 4 stars in Little Navmap. 

Really in my opinion it was '1' star before, and possibly '5' stars now. Possibly the fault of the airport design or x-plane itself for listed as 'helipad', not sure, but could be others the same.

Regarding the 3D airports answer from Julian:

Quote

You may consider the airport to be "3D" if the airport code appears (at the start of an airport group) in:
"Custom Scenery/Global Airport Scenery/Earth nav data/apt.dat"

However, the definition of "3D" is somewhat arbitrary. A "3D" airport may contain just a single object, such as a light fixture, a parked car, or a traffic cone. Alternatively, it may be a fully constructed major airport.

The airport will get no or only few stars if the add-on developer does not add apron polygons or taxiways since he's using other techniques like photo scenery. Can't do much about it. There is no way for me to scan the whole scenery library.

ENBR should not show as heliport. Can you send me the link to the add-on? There is more than one ENBR in the library.

Alex