After AUTOCAD import model will not render textures in full detail (1.3 MB)

Attached model is the result of an autocad 2d import and some simple 3d modelling on top of it. The models will not render textures in detail. Any other model (newly created) will, but as soon as the autocad 2d lines are imported or cut and pasted into the new model, the texterus will not render in detail anymore. Find model attached.
The model is NOT in wire frame or anything similar ?
Does anyone have a clue ?
Kind Tegards,

Check your import unit. Your house is 6 kilometers (6000 meters) high. You are perhaps using Meters as the import unit while the DWG file uses millimeters. All normal textures would be too small to show.