. All of the file required for this tutorial can be found here:

All textures

So, fire up 3ds max, load the file with the finished model and let’s begin.

Select the model and in the Editable Poly options select the Face selection mode. Also be sure to check the Ignore Backfacing option because we don’t want to deselect/select the faces that are on the opposite side of the model.

Rotate the perspective view port (I recommend that you use the perspective view port for all of the operations in this tutorial, because it speeds up the process considerably) so you are watching the model from bellow. Select the faces at the bottom of the house and delete them, because we are not going to need them.

Now, select all of the faces that represent the outside walls of the house.

Next, go to Editable Poly options -> Edit Geometry and click on the Detach button to separate (detach) the selected polygons from the model.

Name it Walls and click OK.

Next, select all of the polygons that are supposed to be windows and detach them (name them Windows). 

Select the polygons from the next picture, detach them as Roof1.

Select and detach as Roof2.

And finally detach the 2 polygons that make the door (name: Door).

Leave the Face Selection mode and rename the remaining polygons to Frames.