8 ways to winterize your Japanese apartment (or house)
1. Insulate those windows!
2. Cover the cracks in the window/door frames
Even in newer apartments, the edges of windows and doors tend to be drafty. Of course, you can use some of your leftover bubble wrap (if you have any) to tape over these areas. Another way to help seal them off is by using すきまテープ (sukima teepu), specifically for placing in these cracks. The cheap kind are made of foam, with a sticky back that you apply in the cracks around the frame. They also claim to keep out dust. Some variations include a special kind of tape (not foam) used for the same purpose (more expensive though).
3. Use a panel at the bottom of windows and doors
A stop panel (ストップパネル) or "cozy" board (ぬくぬくボード) (which may also have other names) is either made of plastic, or thick foam with a reflective silver side that you place against the bottom of the doors or windows. Typically they are labeled somewhere with 窓際 (まどぎわ, madogiwa, essentially "by" or "at" the window). They supposedly keep the warm air in and the cold air out. Though taping is probably best to do first, I have used a foam panel before, (when I used to sleep on a futon on the floor near a glass door), and found it to work better than without. I've also heard long socks filled with beans or rice help with this, in addition to tightly rolled and packed towels.
*Similarly, there are silver reflective sheets mats you can lay under rugs and carpets as well.
*And, in addition to the above, you can also purchase special tape or foam panels that will soak up condensation, if you have a problem with that.
|This is a plastic flap you can put on a door to prevent air flow|
4. Find some thick curtains
My mom always used to pull out the thick winter curtains when the temps dropped - and this was in the States with double-paned windows. If it's really cold, consider purchasing some thick curtains (カーテン), or at least hang up an old, thick blanket to help cut the draft.
5. Get a heater (or heaters...)
Well of course... this is probably anyone's first option. Multiple choices with this one. I personally prefer electric (carbon) and find them to usually use the least energy, but there's always ceramic, halogen, kerosene or oil. Some may be labeled "stove" instead of heater (see below). And if you already own an air conditioner then it's quite likely it has a heating function as well. If none of those are good enough, there's always a wood stove...
ヒーター (hiitaa, heater)
カーボン (kaabon, carbon)
セラミック (seramikku, ceramic)
電気 (でんき, denki, electric)
オイル (oiru, oil)
ストーブ (suto-bu, stove)
石油 (せきゆ, sekiyu, oil/kerosene)
*Sally informed me in the comments that actual kerosene is referred to as 灯油 (とうゆ, touyu). However, Amazon.jp labeled all the gas/kerosene heaters with 石油, though my guess is that if you purchase a regular gas heater, when buying kerosene you will want to look for 灯油, not 石油. (Thanks, Sally!)
For more, check out: How to heat your home and stay warm in Japan this winter and A guide to heaters in Japan.
6. Kotatsu (こたつ)
This lovely invention is a short table with a heater contraption that hangs from the underside. Put a very thick, comforter type blanket between the two panels on top and voila! Good for work or an eating surface, and you can stay warm and cozy sitting under the blanket.
7. If you have a mattress, get a heating pad. Or an electric blanket.
I noticed these are less common in Japan, but fortunately I brought one with me from the States on our last trip home. It's great to never jump into a cold bed, shivering, and doubles for keeping us warm without leaving heaters on all night when it's really cold. However, you can buy electric blankets quite easily at most hardware type stores and sometimes stores that sell housewares. Look for: 電気ひざ掛け毛布 (でんき ひざ かけ もうふ). 電気 means electric and 毛布 means blanket. Amazon.jp carries quite a few.
This isn't exactly something that will provide heat or keep out the cold, but it's a good thing to have during the dry Japanese winter. At least, it makes it easier to breathe at night. We found an air purifier/humidifier combination that auto-detects humidity levels and the quality of the air. You can change the settings of course, if you want it on auto or manual, but it was a good bargain for a 2-in-1. For a humidifier, look for 加湿器 (かしつき, kashitsuki).
Rest assured, there are more ways to keep warm (fleece is amazing...) but I wanted to throw out some ideas in preparation for the cold months ahead. Any other thoughts on preparing your Japanese dwelling for winter?