[elihu]

I think AAC is pretty rare where I am (Oregon) but apparently there's a company in Bend that specializes in it. They're a Hebel distributor.

https://northwestaac.com/

AAC floor and roof panels do exist.

My impression is that ICF is a lot more common in my area than AAC, though it's still not super common compared to, say, stick frame construction. I'd guess that's probably because with AAC you'd need to add additional insulation, whereas with ICF you wouldn't -- but maybe there are other reasons.

[orthoxerox]

AAC doesn't always require additional insulation. The rule of thumb is that a wall X mm thick made of AAC with density X kg/m3 has a metric R-value > 3, which is sufficient for Central Russian climate (which I am told is similar to Vermont, colder than the PNW). I have no idea what kind of blocks are sold in the US and how to convert between metric and imperial R-values, but online calculators suggest that a 300mm thick D300 block should have an imperial R-value of about 18.

Northwest AAC claims even higher values: "[f]or example, the R-value of a typical <...> 12-inch wall is R-29", so either I'm converting the wrong values or the measurement standards are very different across the countries. Xella (Hebel) claims their blocks are warmer than standard blocks, but 50% more sounds like too much.