This 3D model was originally created with Sketchup 13 and then converted to all other 3D formats. Native format is .skp 3dsmax scene is 3ds Max 2016 version, rendered with Vray 3.00 Window cuts two surfaces... Insert thecasement28x72inttrimcomponent on to the exterior face , right click and explode it. The main component will cut the exterior face and an imbedded component cuts the interior face. The interior also has trim.
Copied from http://sketchup.google.com/3dwarehouse/details?mid=13e7cbaf0cca77c647862de315a7202 for testing. Selected both components, moved 4' to right. Works perfectly, no problems whatsoever! See discussion: Discussions > Using SketchUp for 3D modeling > Cutting windows into double walls http://groups.google.com/group/SketchUp3d/browse_thread/thread/c41e1081f0397792?hl=en