Why are Japanese houses so cold in the Winter? And how do you stay warm in one?
Old Japanese houses are not insulated. The opposite, in fact. In the old days, they were heated by small fires inside with vents in the ceiling to let out the smoke. Decades ago people transitioned to kerosene heaters, and those are still widely in use today. Both of these heating methods produce poisonous gases, so houses had to air out for safety reasons. The houses also had to air out because of the humidity. If humidity gets trapped inside the walls in a climate like Japan’s, you get mold. The old houses are made to vent air from underneath the house and up through the hollow walls. Even modern houses and apartments are not well sealed and include vents in the walls you can open to let air freely pass.
The way to stay warm in such a house is to blast heat from a kerosene or natural gas heater. When you’ve got one of those turned way up, it’s like sitting next a camp fire. There’s no way to efficiently heat an old wooden home that is thoroughly ventilated, but those homes are generally small with sliding partitions to make rooms even smaller. So you just heat the small space where you spend most of your time.
You can take it a step further. Japanese homes would traditionally have a small table with a heater underneath (originally they used burning coals). You drape a thick blanket over the table and sit with your legs underneath. Your legs soak up the heat and warm up your whole body. My wife has fond memories of sitting with her feet under the kotatsu while relaxing or doing homework as a child.
What does all this mean in practice? Winters can be very cold in Japan. In the morning, you wake up to a cold house. The first person who gets up starts the heater (unless you’ve got one on a timer) and waits for the room to heat up. If you like to take a shower in the morning, well, you’re going to experience some character development doing that.
But if you are living in Japan in a cold house, here are some tips:
- Natural gas heaters work better, and they are much healthier to have in your house. My first year in Japan we started out the Winter with an electric heater. About February, I bought a natural gas heater instead, and it was like night and day. And learn how to use the timer so it turns on before you wake up in the morning.
- Get some really warm slippers. It’s amazing what a difference they make, and your feet will feel better, too.
- Regardless of what kind of heater you buy, your house is going to get freezing cold at times, so figure out ways to enjoy it. Crawling under a thick, down comforter to sleep at night feels wonderful (after the initial shock before it warms up). Get a kotatsu and experience kotatsu zen. Discover the joy of sitting on a heated carpet.
- Consider showering at night and soaking in a hot tub like most Japanese do, rather than showering in the morning.