On: Wikihouse: Open-Source Houses

[pitaj]

They were referring to insulation in internal walls and floors. That is, the floor between the first and second story or the wall between bedrooms.

[persolb → pitaj]

It's also clear that the floor between levels doesn't have insulation. I'm not sure where the OP got that all the blocks/insulation was the same.

[hkt → pitaj]

Still good if you want zoning etc, but point taken