Issue with textures?

I am completely new to this, so forgive my ignorance. Im an architecture student trying to do some rendering via this software.
I keep getting those textures, does anyone know why? and how to fix it? It seems better when I put the directional light in the scene but whe i press build, it gets ugly again, thanks!

Not sure if this helps, but maybe you could check to make sure all scalability settings are set to max?

the way it looks post build is how it actually looks in the game. im not quite sure what you mean by ugly, but you can change the intensity of the light or turn off cast shadows if thats whats bothering you. You can also try adding (or removing) sphere reflection capture, lightmass importance volume, a skylight, or points lights.

Thanks a lot for your responses, I had a second look and it seems I did a mistake by importing an FBX model straight from Sketchup with no UV mapping etc. I think that messed up a lot of things, I ll try the FBX converter today and see what happens. I got no idea about that stuff but eager to learn.