Faces in solid mode suddely seem to be weidly bugged My problem seems to be simple yet I can't really countinue this project without a solution. 

I've been modeling a building. Then once I switched back from wireframe mode to solid mode and my whole mesh became so weird. Everything seems to be okay in, except that the faces look terrible. If I orbit in the viewport, they - the faces - become half-transparent in various shapes and it all seems bugged, like if I duplicated the mesh and it overlaps itself.





What should I do? I didn't apply any modifier to it except a mirror.
Thank you for the answer.
The reason for this issue is that the viewport clipping start is set to 0. If you go to the properties panel (bottom left on the second screenshot) and make the value greater than 0 (the default minimum that blender will allow you to drag it down to is 0.001 and the default value is 0.1) then the objects will look normal again.