I just got another quote...foam fill...€2000. The sales guy was totally against bonded bead because a) the adhesive in bonded bead corrodes the electrical cabling of wires within the cavity b) the bonded bead will still fall out to some extent if I open a wall later for windows c) if the insulation boards that I already have in the house are not absolutley flush against the wall then the beads (that are dropped from a height) will be 'trapped' behind the boards and not fill the cavities properly. He tells me "99%" of houses have this problem and that is why the foam is a better solution. Is any of this true?? I don't trust the guy to begin with (but the company he represents are all above aboard and certified etc). His original quote was €2250 and I got him to drop it to €2000 in ~20 seconds....then I knew he was really screwing me!