icf foundation cost
The rate for 4 ft foundation walls varies anywhere from $10 to $18 per foot, though depending in your state, area, number of companies that do this type of work the rate may be much higher or lower. At $10/ft for a 30ftx40ft structure, the foundation wall will cost $1,500-$1,800.
I have yet to find a study on SIP construction that matches ICF in any of these areas that insurance companies cover..this alone will reduce if not match the cost from an additional $50,000 ($253 @ 4.5% over 30) borrowed, even if given SIP/EPS (that will leak air) matches ICF in energy cost.