Hi,
I'm working on a custom chiselled window, and I think I understand the rules for making insulated rooms (over half and inner or outer face must be "almost full"). I've made a design I quite like, and it is working perfectly downstairs (in granite). However, when i copy the design for upstairs using plaster it just doesn't work. I'm pretty sure they are identical, except one uses "Granite Dry Stone" and the other uses "Plain Plaster". I have both confirmed that it doesn't work via "/debug rooms hi" and by looking at the block to see if it says "Insulating Block Face". Does anybody know if there are special rules for plaster, or am I misunderstanding something here?