Are you in the insurance business? My understanding of the 80% clause is that if you insure your home for 500K , your replacement value (as determined by the insurance company) can be as much as 500k/0.8= 625k and your under-insurance clause will not be in effect. So if you have a 250k loss they will pay the entire 250k and not be reduced. max amount they will pay is 500k.
Yes, I am in the insurance business. Your illustration is correct. Another way to look at is that if the remaining value of the building is less than 20% of the full replacement cost then you will not get hit with a co-insurance penalty even if you are underinsured. It is important that the replacement value of the building (not the amount of damage) be calculated with pre-storm costs. Repair costs after Irma are up 30-40%. Don't let the adjuster use those values in calculating the replacement cost value for the co-insurance formula.
