Has any one used ICF concrete forms to build an extension any tips and costs?

im goint to build and extension using this method
2,7meters
x 3.700meters
x4.00meters
im going to get the foundation and draining don by a builder earlier i start the build

and prob get a carpenter to do the roof

wil this be cost effectual

any tips

and help
Answers:    Using meters surrounded by your measurements I guess you're not doing job contained by USA?.....ICF method is still relatively new contained by my area, exceptionally few contractors can be trusted to do it right. When done right it is definitely a superior product than any other system. Pre-fab concrete walls are more prevalent than ICF surrounded by my area, and getting hold of popularity. The ICF product I have see i was Nudura. The pre-fab panel were Superior Walls. I prefer the latter.