I have a mesh which has many faces and I want to create a simple mesh around it's shape to kinda form a bounding box around it's parts so that I have less faces and have simple bounds around the object shape.

As shown below I made an example of what I want to do, where a bound where set around the door and one of the seats. I want to know how this can be done for the whole mesh. My blend file can be found [here][2]

[![enter image description here][1]][1]




  [1]: https://i.sstatic.net/cdbau.png
  [2]: https://www.dropbox.com/s/fz6props73q0zkf/simple%20mesh%20around%20complex%20mesh.blend?dl=0