It all depends on your priorities. With the ICF structure, you not only get the R-22-26? continuos insulation, airtight walls, but also the other inherent benefits: fire rating, stc, strength, etc. If those things and the other benefits are appealing, that is the way to go. Can you use steel studs for interior walls?
Given that steel conducts thermal energy, your walls start off at a disadvantage for achieving an energy effcient wall assembly. You can do better than a typical wall assembly by double framing the walls (staggered), paying extra to have wall insulation installed properly, and paying extra for 2x the insulation. (not hating, HERS raters get paid to inspect insulation installations because quite frequently corners are cut to accomodate plumbing & electrical chases, or just out of expediancy - this will come from your lowest bidder - "which is where I get paying extra for proper insulation installation")
Or you could use the recommendation above to be better than average, but still not going to be as energy efficient as ICF.
Again, depend on whether you are looking for better than average or HIGH Performance walls.
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