kotatsu japanese coffee table space heating

Warm Around the World: Kotatsu Space Heating


Instead of heating your whole house … heat yourself.  The Japanese are masters of personal space heating.  Here’s how they use Kotatsu to stay cozy through cold winters despite traditionally under-insulated buildings.  

This post is part of a series on keeping Warm Around the World.  Learn more about winter coping strategies in world cultures here in Warm Around the World: Igloos.  


The principle here couldn’t be simpler, enclose a small space, then heat it up.   You get added benefit from the fact that the blanket or futon itself is an insulator, so even after the heat source is off, it takes a while to dissipate.

The earliest version of this home heating method was as basic as people gathering around a hearth for warmth.  Over time, charcoal burning hearths were sunk into the floor of homes such that people could sit around them with feet in the lower area.  After the fire died down to coals, a blanket could be thrown over the top to trap heat.

People rarely heat or cook in their homes with charcoal burners. Still, the idea has lingered in the modern version of a kotatsu – a low wooden table (a western-style coffee table) with a heating element underneath and a blanket coming out from the edges to cover the legs and feet of people sitting around it.


For traditional Japanese households, the Kotatsu becomes the center of the home in winter, with family gathering around its warmth to eat, study, or just hang out.

This idea has been picked up by a few westerners (typically people who have spent time in Japan) but could stand to catch on more.  It’s a great idea.  Apartment Therapy has featured it as a home space heat technique, and for good reason – people who rent often need small portable ways to control the heat in their living spaces.

dwell kotatsu cropHere the kotatsu concept is demonstrated in modern form – in this Dwell feature of Konishi Gaffney Architects’ design for their own home (designed to suit their Scottish-Japanese blended family).  Since they have in-floor heat, they have forgone the heated table element, but they use the older kotatsu design where there is actually a depressed foot space in the floor to go along with the low table.  It serves the dual purpose of a warm space and a family gathering area. And for the industrious, DIY types, here’s a step-by-step and video tutorial to guide you through the design and construction process.



As we discussed Tuesday, the American heating method – blow in hot, dry air to try to fill an entire house – generally results in warm ceilings and cold floors.  It is far more effective to heat the space right around your body.  While you might not rush out to find or make your own kotatsu, you can improvise one with a cozy blanket and hot water bottle or heated bean bag.

Our office at Moss HQ simulates this system by supplementing our in-floor office heat with a small space heater under the desk level on the coldest days.  With warm legs and feet, everything seems cozier, and it makes so much more sense than filling our 2-story open plan office with enough hot air to get down to our sitting level.  It works for us!

What small area can you space heat this winter to maximize comfort and minimize your heating bill?