Mesh Collisions (Or complex collisions)

I have created a complex house in Sweet home 3D, exported to Blender, builded UVMAps and exported as FBX to UE4,
the exporting way was not modular, i exported all walls into one mesh, floor into another mesh, ceilling into another, and so… So i have few big Meshes…

I need to add almost perfect collision for walls, Windows and door frames… so i guess i have these options:

  1. Splitting the house in Blender into basic shapes and reimport each splitted model into UE, then let UE add its collision automatically.
  2. Import the complex model of my house and edit it inside UE Model editor, then add multiples arranged boxed colliders and Save it…
  3. Import the complex model of my house and créate primitive boxes in the map and them disable visibility on them…
  4. any other way i Will apreciated to read…