Kotatsu Heater: The Japanese Table for Warm and Sustainable Winter Living

If you’ve visited or lived in Japan, you’ll know that – unless you live on the tropical island of Okinawa – Japanese winters are terribly cold. Central heating and insulated walls and windows are uncommon in Japan, except for the northernmost island of Hokkaido.

While the World Health Organization (WHO) recommends that living spaces should have an average temperature of 21°C and other occupied rooms be at least 18°C, many homes in Japan are averaging between 12-17°C.

So, to combat the wintry cold, the Japanese have created a device that only heats the area of your home that you’re actively using. This heating device is called a kotatsu.

These space heaters are a Japanese invention that keeps household members warm throughout the colder months. They have been used for centuries and exist almost exclusively in Japan.

But what exactly is a kotatsu table? How do they work? And can you get one?

Keep reading to find out everything you need to know about the japanese heated table.

How To Use a Kotatsu in Japan

A kotatsu table is typically the center of a home. It’s a type of space heater made from a low wooden table frame covered with a futon or heavy blanket placed over the top and with a heater inside. The heater has space for individuals to tuck their legs in underneath, and the surface is an excellent spot to place several cups of tea or serve a small meal.

To write ‘kotatsu heater’ in Japanese, two symbols are used. The first is a Chinese symbol meaning “torch” or “fire,” and the second is a traditional Japanese character typically meaning “footwarmer.

Although these space heaters have been used for years in Japan and have become an essential piece of furniture in Japanese homes to help weather the winter, there was a dip in kotatsu sales when underfloor heating became popular.

However, with the rising interest in sustainability, green living, and the increased cost of living, kotatsu heaters have been recognized as a cheaper and more eco-friendly option.

The kotatsu remains a popular attribute of Japanese family homes and commonly acts as the center of the house, congregating household members for dinner, tea, or just a chat.

Kotatsu History and The Irori

The kotatsu heater was developed during the Japanese Muromachi period, from 1336 to 1573. The inspiration was taken from already-established irori cooking systems, which can also still be found in Japanese homes.

The original irori system was a pit in the floor with a fire built inside, used for cooking and heating. A wooden frame was soon added to the irori, and a quilt was laid on top to conserve heat.

In the 17th century, the irori was replaced by the portable kotatsu to better heat more of the house. The first portable kotatsu models were made from hibachi pots filled with charcoal and called okigotatsu, literally meaning ‘placed kotatsu,’ referring to the owner’s ability to place it wherever they please.

Today, the portable kotatsu has been industrialized as an electric heater to be more user-friendly and eliminate safety risks surrounding coal and fire in modern homes.

Types of Kotatsu

In modern Japan, two different types of electric kotatsu heaters can be found, which differ in heat type and structure. Japanese families pick their kotatsu based on their preferences and lifestyle.

Electric Kotatsu

The modern okigotatsu (portable kotatsu heater) has a table frame under which an electric heater is fixed.

A futon or heavy blanket is placed over the top to encapsulate the heat, and the table surface is attached on top, which can be used as a writing surface, an eating table, or a place to put a cup of tea.

Charcoal Kotatsu

Although less popular and considered outdated, charcoal kotatsu heaters can still be found in modern Japan.

The charcoal kotatsu can be either fixed or portable, both available with the table or pit design.

The charcoal kotatsu table is designed similarly to the electric kotatsu, with a pot of lit charcoal placed underneath the table. Or, charcoal may be lit in an irori-like pit placed in a central position within the house.

Some houses use a combination, as the irori hearth can be equipped with hot charcoal and electric heat sources.

Kotatsu Designs

Since their creation in the 14th century, kotatsu heaters have served one main purpose – to heat a room and keep its inhabitants warm. The position, additional functions, and aesthetics of traditional heaters have developed over time.

Dining

Even if houses use a portable kotatsu heater, many still keep the heater in one central area and use it as a dining area in the winter. Therefore, the kotatsu heater will often be decorated to fit the aesthetic of the room’s interior.

Kotatsugake

The blanket draped over the heater table can be covered by a second, heavier quilt called a kotatsugake.

The kotatsugake is typically a blanket that provides decoration and can be used to wrap the lower body while using the kotatsu heater. Kotatsugakes come in a wide range of designs and colors.

Whether you prefer a simple, minimalistic design to complement your cushions or a bright kotatsugake to rejuvenate your space with color and funky patterns – the options are endless.

Couch setup

Although frequently used as a dining option, kotatsu heaters can also be made into elaborate couch setups with decorative cushions and additional blankets for eating, entertaining guests with drinks, or reading.

Whether you want a small space for only one or two people or a larger communal area to fit a big family, a kotatsu couch is diverse enough to do either.

Sofa-bed

The sofa-bed design is perfect for you if you have a large or expandable couch and love indulging in comfort and warmth. By placing a kotatsu table in the center of your extended sofa and spreading the blanket across its surface area, you can create the ultimate relaxation spot.

If you don’t have an extendable couch, don’t worry! You can easily buy additional seating panels to add to your sofa, extending its size to accommodate more people and the heater.

This design is perfect for naps, reading, or watching films.

One-person kotatsu

If you live alone or want to create a warm space used for only one household member at a time, the one-person kotatsu is a good choice.

Equipped with a taller table to accommodate someone seated in a regular-sized chair, this design makes an excellent desk and is guaranteed to keep you warm while you work.

The one-person design is a practical option to help keep you warm and productive.

Circular kotatsu

Adopting a circular-styled kotatsu heater is a modern, stylish, decorative option great for hosting. 

A circular table heater is perfect for having your friends round for a coffee and catching up or independent work and reading. The design is similar to the traditional circular coffee table.

Kotatsu with Storage

If you live in a bustling city, especially a densely populated city like Tokyo, chances are your apartment or house lacks storage space.

So, if you have a kotatsu in your house, why not use it as a storage unit too?

Some heaters come with removable tops, opening up space to store books, desk objects, or other items you don’t want lying around the house.

When kotatsu are used as storage, they become harder to move, so it may be an idea to keep your kotatsu storage in one place and double it up as a coffee or dining table.

Where To Buy a Kotatsu Heater

Kotatsu can be found in many designs and with various functionalities. So, where can you get one?

The space heaters can be purchased online, or you can make your own with the right-sized table, a space heater, and a blanket.

Of course, this assumes you have the time, patience, and skills to make your own heater – otherwise, steer clear of any DIY projects and find the perfect kotatsu for your home and lifestyle by purchasing one online!

Whether you decide to purchase or make your own, always follow safety precautions to avoid burns and the risk of fire. Don’t leave the heater unattended even if modern kotatsu are usually safe to use; monitor children and pets when it is in use.

Purchase Online

Ready-made kotatsu heaters are easily available online from independent Japanese stores or eCommerce providers like Amazon.

DIY Kotatsu

However, the more practical option is to buy the different components that make up the heater separately and assemble them for maximum customization.

1. Buy a Functional Table

Look online to easily find tables perfect for any kotatsu usage you have in mind. Whether you’re after a foldaway table or a permanent, high-quality table, there are products out there that will be a perfect fit.

Japanese companies like ‘Yamazen’ and ‘Azuyama’ are great companies that specialize in producing and manufacturing tables for use with kotatsu heaters. These companies make tables using quality craftsmanship, prioritizing durability and functionality throughout production.

2. Buy an Electric Heater

Electric heaters can be found in most hardware stores or online. Make sure to buy an electric heater that can be fixed to the underside of your table, and be sure to purchase a good-quality heater to prevent malfunctions or accidents.

Specific kotatsu are available for online purchase on Amazon. Look for an option that guarantees functionality as part of the heater setup.

3. Add a Futon, Blanket, or a Rug

Futons, blankets, or rugs can be found in soft-furnishing stores or online. Be experimental with the patterns, colors, and designs for the style you love and the function you prefer.

Designer brands like Emoor make high-quality and pretty futons, blankets, and rugs that can be used on top of the kotatsu table. To maximize comfort, you may consider purchasing a few blankets instead of just sitting on the traditional (but thin) tatami mat.

Pros and Cons of Kotatsu

The kotatsu space heater creates a warm ambiance in any space, but it’s not for everyone or every area. Here are the pros and cons of the heater to review before including one in your home.

Pros

The kotatsu is best loved for its gentle warmth and beautiful looks.

Functional Warmth

Keeping warm in cold Japanese winters can be difficult due to the lack of insulation in Japanese architecture. But the space heater puts out just enough warmth to keep small spaces warm without using too much energy.

Staying warm can keep you from developing health concerns, and the cozy atmosphere creates an inviting space to host and spend time with family.

Energy Saver

Instead of using central heating systems, kotatsu can keep you warm for a fraction of the price and help save energy, making them a greener heating solution.

Cons

The kotatsu is a space heater that can easily be knocked over, leading to burns and fire. The heater isn’t for every space and family!

Not Recommended Around Small Children and Pets

The space heater can easily be knocked over, so children and pets should always be monitored when they’re near the heater if it’s in use.

Safety Risks of Falling Asleep

The space heater’s warmth can be so relaxing that users might fall asleep and may accidentally knock the heater over, increasing the risk of a burn or fire.

Place the heater in a safe place and take precautions, such as sleeping a distance from the heater and having working fire alarms to avoid an emergency.

Choosing a Kotatsu For Your Family and Your Space

While there are some safety precautions to consider when using the kotatsu, the product is commonly used and loved throughout Japan. It can make cold winters tolerable and help users relax or boost productivity.

No matter which design you choose and what you use your kotatsu heater for, there’s no doubt it’ll significantly contribute to your living space!