range extender

I am working at a house that has the Wifi using a netgear nighthawk router.  The house is technically 2 story.  Need to extend to the lower basement area.  These are block walls and the lower floor is actually under a concrete pad/porch deck.  The router is near a window that overlooks the lower floor.  Tried with a powerline adapter but while the is only 1 meter the 2 sections have their own subpanels and the signal did not travel through.  Any suggestions?