House has no colliders?

Okay, so i made a house in sketchup but when i export it to unity it has no collisions, i can walk through the house and floor and it’s like it has no walls, however, i tried adding box collider, but then i can’t enter the house because it’s “box” and how can i make it has collisions? This is a bit annoying :stuck_out_tongue: I also tried in inspector apply collisions but seems there are no buttons like that. Anyone help/know what’s the problem?

SCREEN:

You’ll need to separate the house into individual rooms and pieces, and probably apply a mesh collider. Unity won’t automatically generate a perfect collider, this is one thing you have to define yourself.

I TRIED TO MAKE A HELLO NEIGHBOR FANGAME BUT THE HOUSES DONT COLLIDE