eh? no i dont agree that using multifoil insulation systems are more expensive than using Rigid insulation alone. If fibre insulation + reflective insulation is combined to get appropriate thermal value i believe this is the most cost effective solution
I would like to address several points raised in this discussion:-
1) Why it is not better to use rigid insulation boards
It is not cheaper to use PIR board insulation there are many factors which make this more expensive than other methods
a. material
b. time to cut each board...