Create surface by lines

I have to create the frames for the cabin of my boat.

  • How can I be extruded frame with equal distance from the cabin (es.1)

second question:

  • How can I create frames for the large window to extrude (Es. 2)?
    Create frame to be extruded and then make union with boolean to make solid

Thank You
cabin.3dm (1.0 MB)