Tatami room is what most English speakers call a washitsu. The Japanese-style room has wall-to-wall tatami flooring and sliding doors, so the same space can be a living room in the afternoon and a bedroom at night, and it doubles as the guest room whenever someone visits.
Size comes in mats, not square meters. The floor is woven rush grass over a rice straw core, which is the main thing separating it from the Western-style yoshitsu.
Ryokan and temple guest halls still use the room daily, as do plenty of older family homes. The materials behind it are getting harder to find, though. Only 18 percent of tatami coverings were made in Japan in 2025, against 70 percent in 1996 (Nippon.com, 2026).
What Is a Washitsu?
Literally, the word means “Japanese-style room”. Where a Western room would have hinged doors, a washitsu has sliding ones, and the floor is covered in tatami mats.
Nihonma is another Japanese term for the same thing. The opposite is yoshitsu, a Western-style room with wood, tile or carpet floors.
In Japanese homes built the traditional way, almost every room was a washitsu. Many houses still keep one, often set aside for guests, and many newly built apartments have none.
What a washitsu is not
A room with a rug and low furniture doesn’t qualify. The floor system and the sliding partitions make the room, not the look.
A single loose mat on a hardwood floor changes nothing either, since tatami is laid wall to wall in a layout planned for that room.
And it isn’t only a bedroom. The same space switches between sitting, dining and sleeping.
Outside private homes, you find them in ryokan and temple guest halls, and some old folk house cafes keep one too (JEEPE).
Which Features Define a Washitsu?
Wall-to-wall tatami flooring and sliding partitions between spaces are non-negotiable. The tokonoma, oshiire, ranma and engawa show up often but are optional.
Tatami flooring
One mat can absorb up to 500 milliliters of moisture and release it when the air dries, according to Nippon.com (2026). Humidity buffering is built into the floor itself.
- The core is compressed rice straw
- Woven igusa rush grass forms the surface
- A cloth border called heri runs along the edges
- Most mats are 5 or 6 cm thick (Japan Living Guide)
- Each mat is twice as long as it is wide, which lets mats tile in several layouts (Fun Japan)
A closer look at how tatami mats are built and graded explains why quality varies so much between a cheap rental and a temple hall.
Fusuma and shoji
Fusuma divide rooms. Shoji let light in.
Fusuma are the opaque panels, often painted, that separate one room from the next. At the windows and outer edges you get shoji instead, a wood lattice with translucent paper stretched over it.
Lift out the sliding fusuma panels and several small rooms join into one large space, as Prince Hotels describes it.
Tokonoma, oshiire, ranma and engawa
The tokonoma is a raised alcove for a hanging scroll or flower arrangement, usually found in the guest room. Futon go into the oshiire closet during the day. Above the sliding doors sits the ranma, a carved transom that lets light and air through, and along the outer edge runs the engawa, a narrow wooden veranda.
Remove all four and the room is still a washitsu. Remove the tatami and it is not.
How Is the Size of a Washitsu Measured?
Washitsu size is counted in jo, the number of tatami mats that fit the floor, so a 6-jo room holds six mats. Half-size mats allow rooms such as 4.5 jo, and 6 and 8 jo are the typical sizes in private homes (Wikipedia).
A few figures are worth keeping handy.
- A Kyoma mat measures 191 x 95.5 cm
- An Edoma mat measures 176 x 88 cm
- Mat thickness is usually 5 to 6 cm (Japan Living Guide)
- Listings must count at least 1.62 sq m per jo, measured at wall centre (Akiyajapan, 2026)
| Standard | Where used | Mat size | Area per mat |
|---|---|---|---|
| Kyoma | Kansai, Chugoku, Shikoku, Kyushu | 191 x 95.5 cm | 1.82 sq m |
| Chukyoma | Aichi, Gifu, Mie, Fukui | 182 x 91 cm | 1.66 sq m |
| Edoma | Kanto and east, now nationwide | 176 x 88 cm | 1.55 sq m |
| Danchima | Public housing blocks | 170 x 85 cm | 1.45 sq m |
Why the jo count alone says so little
Six Kyoma mats cover 10.94 sq m, while six danchima mats cover 8.67 sq m. That is a gap of about 26 percent (Benri.dev, 2026).
An independent tatami calculator shows the same spread on a 10-jo room, from roughly 14.5 sq m to 18.2 sq m. Two separate calculations landing near a quarter of the floor area settle it. The jo count alone says little about space.
The gap has a construction reason. In Kansai, builders set the pillars around fixed mats, while in Kanto the pillar spacing came first and the mats were cut to fit (Rakuten Travel).
What the legal listing minimum says
Under Article 9, item 16 of Japan’s advertising regulations for real estate, one jo in a listing must mean at least 1.62 sq m. The figure is the room’s wall-centre area divided by the mat count (Akiyajapan, 2026).
- A listed 6-jo room needs at least 9.72 sq m of wall-centre area (6 x 1.62)
- Six Edoma mats come to about 9.3 sq m of actual mat floor
Both numbers are legal because they measure different things. Some calculators label Edoma as 1.62 sq m, which mixes up the advertising floor with the physical mat.
To compare two rooms, skip the jo count and compare the square meters.
Where Did the Washitsu Come From?
The washitsu took shape in the Muromachi period (1336 to 1573), when the shoin, a study, grew into a formal reception room.
Sources disagree on the start. ArchDaily, citing Gunter Nitschke, ties its emergence to the Kamakura and Muromachi periods and the dry landscape garden, while japan-guide.com places the origin in the Muromachi period as a study room for the wealthy.
From one mat to wall-to-wall tatami
Before the shoin spread, a single tatami was brought out only for the highest-ranking person in the room (Wikipedia, citing Welch). Shoin rooms then covered the whole floor with mats.
Floor plans, door proportions and ceiling heights were drawn around the mat. The mat module came first and the room followed.
The oldest surviving example
The Togudo at Ginkaku-ji in Kyoto, dated 1485 in most references, is the oldest surviving shoin-style building (Wikipedia, citing JAANUS). Some sources, including Japan’s tourism agency database, give 1486 for its completion.
Inside is Dojinsai, a 4.5-mat study that japan-guide.com treats as the prototype of the 4.5-mat tea room.
Tea houses and sukiya-zukuri
Tea houses developed alongside shoin-zukuri. In the Edo period the two sets of features blended into sukiya-zukuri, an informal version of the shoin style (Wikipedia).
A dedicated room for the tea ceremony keeps the same mat-based logic at a smaller scale.
Reception rooms in the shoin tradition also gained a tokonoma display alcove, which is why guest rooms still carry one today.
How Is a Washitsu Used, and What Etiquette Applies?
A washitsu works as a living room, dining room, guest room and bedroom in turn, because nearly everything in it moves. The floor stays put while the furniture comes and goes.
Sleeping, dining and seating
- At night, futon go down on the tatami, and in the morning they fold away into the oshiire
- Meals, tea and conversation happen around a low chabudai table (X-House)
- Winter brings out a kotatsu, since most Japanese homes lack central heating (Wikipedia)
- For seating there are zabuton cushions, or zaisu, the legless chairs with a back
Seiza, kneeling with the weight on the lower legs, is the formal posture. It becomes painful for people unused to it, which is why many choose a zaisu with back support. Honestly, the zaisu is the sensible pick for anything longer than a short visit.
Sleeping follows the same logic, and futon bedding laid straight onto the mats turns the room into a bedroom with no bed frame.
In winter the room gathers around a heated kotatsu table, with a blanket over the frame.
Etiquette for guests
Slippers come off before the mat, not at the room door.
- Take off outdoor shoes at the genkan.
- Wear the provided slippers through the corridor, then leave them at the edge of the tatami.
- Step onto the mat in socks or bare feet.
- Step over the heri instead of onto it.
- Lift luggage rather than rolling it, and keep it out of the tokonoma.
- Kneel on a zabuton instead of walking across it, and step off onto the tatami when you stand.
The border rule has several explanations. The most cited is that family crests were once woven into the heri, so stepping on one was disrespectful, while another is that the cloth edge wears easily (JEEPE, 2026).
Door tracks (shikii) fall under the same rule, but sources split on the reason. SoraNews24 (2019) gives two: the room counts as a space separate from the rest of the house, and stepping on the groove can warp it.
Washitsu vs Yoshitsu: What Separates a Japanese-Style Room From a Western-Style One?
Tatami floors, sliding partitions and furniture at floor level mark a washitsu. In a yoshitsu you get wood, tile or carpet underfoot, hinged doors and the usual chairs and beds.
| Attribute | Washitsu | Yoshitsu |
|---|---|---|
| Floor | Tatami | Wood, tile or carpet |
| Doors | Sliding fusuma and shoji | Hinged doors |
| Seating | Zabuton or zaisu on the floor | Chairs and sofas |
| Bedding | Futon, stored by day | Fixed bed |
| Function | Multi-purpose, often the guest room | Dedicated bedroom or living room |
| Size unit | Jo | Jo in listings too, or square meters |
The door type changes how the rooms connect. Sliding doors need no swing space, so a washitsu can open onto the living area and extend it by day.
Why most modern homes keep only one
One homebuilder’s site showed about 60 percent of its single-family homes built in 2018 included a washitsu, a share that fell below 40 percent by 2022, and almost no Tokyo high-rise apartments have one, according to Nippon.com (2026).
Buyers and renters now often pick an extra Western-style bedroom or a larger living-dining-kitchen area instead (Housing Japan, 2023).
Designers keep the idea alive in modern Japanese interiors through partial versions of the room. One approach is tatami laid over part of a Western-style room and used for sleeping (Nippon.com). Others build a raised tatami platform beside the living room, or use Ryukyu-style tatami, square mats without the heri.
Trade-offs by room type
Washitsu upsides
- One room handles sleeping, guests and meals
- Rent is often lower in older buildings, because demand has dropped (SUGEE Housing, 2025)
- Suits tea ceremony and family altar use
Washitsu downsides
- Regular vacuuming and periodic resurfacing are part of the deal
- Mold and dust mites like it as much as people do (SUGEE Housing, 2025)
- Heavy furniture dents the mats
Yoshitsu upsides
- Beds, sofas and desks sit directly on the floor
- The layout matches most newly built homes
Yoshitsu downsides
- Sleeping, sitting and dining each need their own furniture
- It rarely doubles as a guest and tea room
Pick a washitsu when one flexible room matters more than furniture freedom.
How Do You Care for a Washitsu, and When Does It Not Work?
Vacuum along the grain and never wet-mop. Keep humidity below 60 percent. That covers most of what keeps tatami in service (Japan Handbook, 2025; Tatami Mat Net).
Daily and seasonal care
- Vacuum along the grain with the beater brush off
- Wipe with a dry cloth, or one wrung out well
- Open windows on clear days to release humidity
- Run a dehumidifier in the rainy season
- Hang curtains if direct sun is fading the mats
| Renewal method | What happens | Typical timing |
|---|---|---|
| Ura-gaeshi | Surface flipped to the unused side | 3 to 5 years after installation |
| Omote-gae | New woven surface on the old core | Once the flipped surface wears |
| Full replacement | New mat with a new core | About 20 years |
Kyo Tatami (2026) and Japan Handbook (2025) agree on the flip and replacement figures. One maintenance checklist puts full replacement at 10 to 15 years, so heavy use pulls the schedule forward.
When a washitsu is the wrong choice
A washitsu fails in damp rooms with poor airflow.
Because these are natural materials like rush grass and rice straw, moisture is the main threat. The mats buffer humidity only up to a point, and standing moisture breeds mold (Engineer Fix, 2025).
If mold does show up, vacuum the spot, spray ethanol, scrub gently along the grain with a toothbrush, then vacuum and dry (Mailmate, 2026). One guide allows diluted chlorine bleach instead.
Furniture matters too. Low pieces that spread their weight, such as a kotatsu, suit tatami, while heavy fixed furniture leaves dents (SKDESU, 2026).
Money is the other sore spot. Japan-made igusa coverings now cost two to three times more than imports, and imports supply most of the material (Nippon.com, 2026).
Washi paper or resin faces resist stains and fading, and a mat supplier recommends them for humid homes (Japan Handbook, 2025; Tatami Mat Net).
For a damp, poorly ventilated room, a washi or resin face beats real rush grass.
Washitsu FAQ
Why are shoes removed before entering a washitsu?
Japanese homes treat the outside as dirty and the inside as clean, and outdoor footwear damages the soft rush surface of tatami. Shoes come off at the genkan, the entrance hall, before anyone steps up into the house.
Is it comfortable to sleep on tatami?
Yes, with a futon on top. Tatami feels neither too soft nor too hard underfoot (Prince Hotels), and a 2013 Nifty survey found 50 percent of respondents slept on futon laid over tatami (Nippon.com, 2026).
Can you sit directly on tatami without a zabuton?
Yes. Prince Hotels notes that sitting directly on the mat is fine, and a zabuton is an optional cushion rather than a requirement.
Use one at a ryokan or formal occasion, where it is the expected seat.
How much does it cost to re-cover or replace tatami?
Surface replacement runs about 9,900 to 19,800 yen per mat on a published Nara price list (Kyodo Home Service, September 2025), with a flip costing 6,600 to 7,700 yen. Removing the old mats adds 1,980 yen each.
Another shop quotes 5,000 to 30,000 yen per mat across grades, so rush origin and quality drive the price.
Deciding Whether a Washitsu Is Worth Keeping
A washitsu earns its place when one flexible room replaces two dedicated ones, such as a guest room and a bedroom, and when the household can ventilate the floor and budget for resurfacing.
Start with humidity and airflow. After that, decide between a rush grass face and a washi one, and leave floor area in square meters for last.
Humidity leads because a damp room rules out real rush grass, and the mat face then sets the budget. Re-covering a 6-jo room at 2025 Nara list prices costs about 59,400 to 118,800 yen, plus 11,880 yen to remove the old mats.
The trade-off is furniture freedom, since heavy pieces dent the floor. Those prices come from a September 2025 list, so confirm current quotes as of October 2026 before committing.
Once the room is settled, ideas for decorating a Japanese-style room cover the low furnishings that suit the mats.
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