I'm not sure if it's in issue of just the viewer or the model itself, but it seems to be missing one of the sides of its octagonal shape which you can just see through.
Its birth and death animations are pretty disappointing with the birth simply putting dust around it and the death just lowering slightly then disappearing.
The whole building part itself could stand to be more creative; every face of it has the same part of the same texture wrapped onto it in the exact same way.
A building model was probably not the best choice for your first model; they're a bit more complicated to do properly and not very useful unless done perfectly because of how crucial their animations are and how they generally can't simply have some unit's set of animations given to them like a unit model can.
Because of the animations lacking very much this is not very useful as a building model, despite looking pretty cool.
Good job for your first model, but I believe it should definitely be improved so it can get the 5/5 it has the potential to earn.
Until then, the current version of it is only able to get a 2/5 from me.