When I went to Kunming, well over a year ago, I searched for an apartment. I was annoyed by the fact that all the apartments were huge compared to what I had in Japan. Then I ended up getting an apartment even larger than what I wanted or needed (2 bedrooms), because the location was far better than the one bedroom apartments I looked at.
Winter was cold for me. But even if the apartment had been built with insulation, I still did not have enough things to fill up the apartment. I had one huge empty room that just had a lot of floor space to be cleaned.
I was surprised to read that Japan actually doesn’t have the smallest new homes of industrialised countries. Ireland and the UK do. Granted, they seemed about the same as Japan to me, but they do seem to know that lots of space can be expensive and a pain to keep warm (or cool if living in a better climate).