Primitive pit hut detail Free 3D model

This 3D model was originally created with Sketchup 8 and then converted to all other 3D formats. Native format is .skp 3dsmax scene is 3ds Max 2016 version, rendered with Vray 3.00 The primitive hut had been standard in architectural theory since Vitruvius. How did the first hut looked alike? In this version, the hut is build underground as a pit with all natural materials, but with maximum comfort.