I feel like Japan would be a great importer of Snuggies.

@Oeconomist Yeah, I don't like the idea of overinsulation either. My home country is full of moldy houses because they were practically wrapped in plastic. However, there're quite a few sensible choices between zero and hundred.

@Kaarme—

I grant that the marginal cost of heating the whole room to a more comfortable temperature drops with increased insulation, but over-insulated rooms are a health hazard.

If the building had a higher level of insulation, the kotatsu wouldn't be so... entrapping.