ICF homes are NOT built from concrete panels.
The system uses polystyrene blocks, like Lego. These blocks have transverse reinforcing bars. Steel reinforcing bars are placed down from the fop with a loop on the top floor to ties down the roof. The first story of the 'Lego" blocks is built first. The the pumper truck comes in and the concrete trucks start to roll. and fill the the insides of the blocks. This goes very quickly. Then the floor trusses are placed and the second story "Lego" construction begins. After placing the reinforcing bars the the pumper truck returns and the upper story walls are filled with concrete. So now you have a strong house with 6" concrete walls, insulated inside and out, just like that, ready for the roof trusses, windows and internal framing. Because of the insulation of the Polystyrene the concrete cures slowly, which makes it much stronger.
There are wings on the horizontal bars to take the screws for the siding as nails are no use. Diamond coat siding is required, made in Two Harbors MN, with has a rear spine so it can not bend.
There are a number of systems. Logix, an Canadian system
is widely used in outstate Minnesota now, but not so much in the Metro. We used Diversifoam, of New Rockford MN. They got bought by an outfit, Kingspan, from County Cork Ireland who closed the plant. They make concrete panels, and I think this was an anti-competitive move.
And that's the short quick version.