[SOLVED]What would be the best way to duplucate these shapes?

I need to duplicate these shapes and move them to the other side of the door. What would be the best way to do that?

This is the room Im trying to remodel:

Use the mirror modifier, cut the room in half, work on one half and mirror modifier with do the job.

Thanks for the quick reply, I tried that but the problem is that the meshes is spereated. I managed to get them somewhat symmetrical with