# Why do traditional Japanese homes use sleeping floor mats? **URL:** \ **Category:** Factual Questions\ **Created:** [January 23, 2026, 11:30pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967 "2026-01-23T23:30:44Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Omar\_Little](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/omar_little/32/269_2.png) [@Omar\_Little](https://boards.straightdope.com/u/Omar_Little)\ **Post date:** [January 29, 2026, 8:27pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/61 "2026-01-29T20:27:34Z")
Interestingly, the Japanese discuss room sizes in how many tatami mats will fit on the floor, as opposed to square meters or square feet. Just one of the cultural difference that exists. ---
**Author:** ![icon](https://avatars.discourse-cdn.com/v4/letter/i/c6cbf5/32.png) [@icon](https://boards.straightdope.com/u/icon)\ **Post date:** [January 29, 2026, 8:44pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/62 "2026-01-29T20:44:10Z")
And yes, it is used for “in my day” discussions. As in, when I was your age, I lived in an three tatami room apartment! After no doubt walking uphill both ways in 2 meters of snow. `//i\\` ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [January 29, 2026, 9:45pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/63 "2026-01-29T21:45:00Z")
> [@aceplace57](#): > > I’ve recently read Japan’s rural cities are depopulating. People move to the cities. > > It’s the same here in the US. > > [Rural houses in Japan are going cheap.](https://www.oldhousesjapan.com/) > It doesn’t sound like they’re good candidates for flips and renovations. > > It’s a different engineering model compared to our US brick homes. Not flips, but occasionally they are renovated based not on being a cheap buy but because a family wants to live out there. Renovations are usually expensive and lengthy, because old country houses tend to be left to fall apart when the family moves out. The phenomenon is fairly well documented on YouTube, for example, with channels like Tokyo Llama. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [January 29, 2026, 9:56pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/64 "2026-01-29T21:56:44Z")
> [@puzzlegal](#): > > That’s probably _changed_ since the post was building boom, and i bet that more of the residential buildings are designed to last longer, especially large apartment buildings. In my observation, although new stuff tends to be more western-type and durable, there’s not a lot of new building in the way of single-family homes. In the aggregate, the population is migrating toward urban centers and more multi-unit dwellings. A lot of the housing stock in the countryside is simply abandoned. As in, abandoned for 30+ years and collapsing, as the residents have passed away and the heirs have no interest in occupying the property, or the ownership is clouded and nobody cares enough to cure it. That’s just what I’ve seen in the places I frequent, could be totally different elsewhere. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 29, 2026, 10:25pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/65 "2026-01-29T22:25:00Z")
> [@Omar\_Little](#): > > Interestingly, the Japanese discuss room sizes in how many tatami mats will fit on the floor, as opposed to square meters or square feet. Just one of the cultural difference that exists. If you stay in a tatami may room, it’s incredibly obvious how many tatami mats are on the floor. That’s how i think of the traditional hotel rooms I’ve stayed in. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 30, 2026, 12:08am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/66 "2026-01-30T00:08:30Z")
> [@Sage\_Rat](#): > > A simple wood building might be 20 years, a concrete building with steel reinforcement might be more like 40-50 years. This is simply nonsense and posting things such as the wild claims such : > [@Sage\_Rat](#): > > If someone wants a mortgage for a property, I understand that the banks will deny it on the basis that there’s a “wreck of a building” on the lot. No. No. No. We were approved for 60-year old house that we are remodeling. The remodeling actually costs more than the house, but they still would have approved a loan for just the house and land if needed. > [@Sage\_Rat](#): > > Someone could pay cash for the whole deal but, if the local government decides that the building is a risk to public safety, then they’ll condemn and demolish it. Where do you come up with this nonsense? Even a 30-second search shows how absurd these claims are, just as googling shows surveys reporting a majority of Japanese now sleep on beds. Also, your own site contradicts you, if you actually read it. One term to use is akiya 空家 (literally empty house) but more like abandoned house. These are older homes that no one lives in anymore. Because people are moving from the countryside to metropolitan areas, there are a lot of these abandoned houses and small towns and even cities outside of Tokyo, Osaka, etc. Local government offers subsidies for people to buy these homes. They have websites so people to search for these homes and help introduce the buyers and sellers. We took advantage of this program and bought a 60 year old house. The house was livable, but old fashioned, and the upstairs wasn’t really great, so we are remodeling it, and as I said, we got a loan for remodeling. In the area I live, most of the homes are 50 to 60 years old. It’s true that Japanese houses have shorter lifetimes than many western houses do. My family‘s house in Salt Lake City is at least 120 years old, so having houses that are 60-years old being considered “old” is different. However, it’s not this crazy assertion that houses must be torn down after 20 years. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [January 30, 2026, 12:37am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/67 "2026-01-30T00:37:22Z")
I have no dog in this fight. As said, this is what I’ve read. E.g. a cursory search finds content like the below: > **[Real Estate Japan Picture of the Day - How long is the "life" of a house in...](https://resources.realestate.co.jp/living/real-estate-japan-picture-of-the-day-how-long-is-the-life-of-a-house-in-japan/?hl=en-US)** > > A house being demolished in Tokyo, July 7, 2020. Compared to most other countries, the average lifespan of a house in Japan is shorter due to tax depreciation rules. If it’s AI generated content that’s generated a bunch of fake but consistent websites then I’ve no idea what the purpose was. If it’s a mischaracterization then I’d ask you to explain the nuance. I haven’t looked into it enough to call myself an expert - and didn’t - you asked me to keep expounding on the topic, despite. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 30, 2026, 12:41am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/68 "2026-01-30T00:41:41Z")
> [@icon](#): > > And yes, it is used for “in my day” discussions. And no, it’s often used now even in new apartments and houses to describe the size of rooms even with all Western style flooring. They often give both tatami mat size and square meters. One reason is that houses and land are usually measured in the traditional measurement of 坪 which is two tatami mats and 3.3 m2. > [@icon](#): > > At lot of the construction for new houses is for multi-generation families. Cite? > [@Sage\_Rat](#): > > So while there is some room to wiggle around it, only fanatics with lots of cash are likely to make use of it. No. Just no. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 30, 2026, 12:49am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/69 "2026-01-30T00:49:59Z")
> [@TokyoBayer](#): > > And no, it’s often used now even in new apartments and houses to describe the size of rooms even with all Western style flooring. > > They often give both tatami mat size and square meters. > > One reason is that houses and land are usually measured in the traditional measurement of 坪 which is two tatami mats and 3.3 m2. That makes sense. It’s a totally standard size. It’s a very human-scale size (literally, about as much space as you take up sleeping, if you don’t stretch out too much.) it’s fairly easy to visualize splitting up a room into tatami mats, and thinking about what you could put where. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 30, 2026, 12:51am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/70 "2026-01-30T00:51:54Z")
> [@TokyoBayer](#): > > One term to use is akiya 空家 (literally empty house) but more like abandoned house. > > These are older homes that no one lives in anymore. Because people are moving from the countryside to metropolitan areas, there are a lot of these abandoned houses and small towns and even cities outside of Tokyo, Osaka, etc. There are a lot of these in Europe, too. I visited friends who bought a castle in Italy a year ago. As we drove around, they pointed out “dead houses”, mostly available to purchase for €1, plus tons more to make them livable. I think it’s a symptom of a shrinking population that wants to live in the city, more than having anything to do with traditional construction techniques. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [January 30, 2026, 1:00am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/71 "2026-01-30T01:00:32Z")
> [@TokyoBayer](#): > > However, it’s not this crazy assertion that houses must be torn down after 20 years. I feel like you read more into what I wrote than what was there. A denied mortgage (if true) would be unique to Japan but a building getting condemned and destroyed by local government is something that happens in the US. Saying that doesn’t imply that there are bands of government agents cruising around, looking for excuses to knock things down at the slightest whiff of opportunity. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 30, 2026, 1:16am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/72 "2026-01-30T01:16:45Z")
> [@puzzlegal](#): > > I think it’s a symptom of a shrinking population that wants to live in the city, more than having anything to do with traditional construction techniques. And this is part of it. Like anything else in the real world, it’s complicated. One major difference that most people here are completely unaware of were the major revisions in earthquake codes that occurred in 1983. One major difference that most people here are completely unaware of were the major revisions in earthquake codes that occurred in 1981. The changes took place so buildings and houses built before June 1, 1981 → 旧耐震基準 (old seismic standard). however, this isn’t absolute, and homes that were built by the old standards still can be sold, still can be an insured, and they aren’t torn down by the government, as had been claimed. Some banks won’t provide loans, and some will but will have restrictions. However, others will provide loans. See my previous post. It does affect the price, of course. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 30, 2026, 2:57am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/73 "2026-01-30T02:57:25Z")
> [@TokyoBayer](#): > > One major difference that most people here are completely unaware of were the major revisions in earthquake codes that occurred in 1981. When I use speech to text on my iPhone, sometimes it doubles the content and I didn’t catch it. The 1981 date is correct. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [January 30, 2026, 3:17am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/74 "2026-01-30T03:17:52Z")
> [@abcdefghij](#): > > I was relieved to decrypt that to octopus head (I didn’t know back then how smart 🐙 are). Never, ever order “Dancing Squid” famously served in Hakodate. The squid is quite dead but the salt in the shoyu poured over it makes nerves fire. > **I'm gonna two-click it** > > [https://youtu.be/dxQmOR\_QLfQ](https://youtu.be/dxQmOR_QLfQ) ---
**Author:** ![icon](https://avatars.discourse-cdn.com/v4/letter/i/c6cbf5/32.png) [@icon](https://boards.straightdope.com/u/icon)\ **Post date:** [January 30, 2026, 3:43am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/75 "2026-01-30T03:43:11Z")
> [@TokyoBayer](#): > > And no, it’s often used now even in new apartments and houses to describe the size of rooms even with all Western style flooring. No? I was not making an assertion that they don’t use tatami as a measurement today but that it is used by older generations to tell their children of their humble beginnings. It would not make sense to do so unless the newer generation knows what is meant by that. > [@TokyoBayer](#): > > Cite? You have a point, it is anecdotal from what I have seen around where I live/visit. Since it is more of a rural (or maybe sub-rural? I have a hard time calling it a suburb since it isn’t quite that) so I am sure it varies by locality. `//i\\` ---
**Author:** ![abcdefghij](https://avatars.discourse-cdn.com/v4/letter/a/43a26b/32.png) [@abcdefghij](https://boards.straightdope.com/u/abcdefghij)\ **Post date:** [January 30, 2026, 3:44am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/76 "2026-01-30T03:44:35Z")
> [@DesertDog](#): > > Never, ever order “Dancing Squid” famously served in Hakodate. How do you say “Ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn” in Japanese? ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [January 30, 2026, 3:48am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/77 "2026-01-30T03:48:50Z")
Just like it’s spelled. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 30, 2026, 11:45am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/78 "2026-01-30T11:45:57Z")
> [@icon](#): > > No? I was not making an assertion that they don’t use tatami as a measurement today but that it is used by older generations to tell their children of their humble beginnings. My bad. I misunderstood your post as to mean that it’s not used now except to refer to tatami rooms rather then as a unit of measurement. > [@icon](#): > > You have a point, it is anecdotal from what I have seen around where I live/visit. My impression was that this is not the case very much in Tokyo, where land prices are way too high for that for houses with two entrances. I didn’t see any real good numbers online, but my real estate friend guessing only a few percent of total houses built are the style with separate outside doors. He lives in Kyoto so it may be more common in rural areas. One web site says that that having grandparents living in an arrangement like that affects the eligibility of the child to be put in daycare, something in short supply in large cities, and that many families chose to have grandparents live nearby. Of course, the percentage of people owning detached homes in Tokyo is already much smaller than in the countryside. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [January 31, 2026, 1:10am UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/79 "2026-01-31T01:10:38Z")
From a Japanese friend, my translation > I think one of the main reasons is the major change in housing. > > In the past, houses had many earthen walls and shoji screens, and air was naturally ventilated through gaps. However, because people disliked the cold in winter, modern houses have eliminated these gaps and become airtight. As a result, mold and dust mites began to develop in tatami mats, and the number of tatami rooms decreased. Consequently, the use of beds have spread rapidly over the past several decades. Other friends have said that mold and dust mites were quite a problem and flooring is easier to keep problem free. I don’t know much at all about earthen wall construction outside of a few YouTube videos where they are getting town down in renovation projects. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [February 7, 2026, 4:53pm UTC](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967/80 "2026-02-07T16:53:04Z")
Sleep Number all the way. My wife and I each get comfortable sleep, and it’s easy to get up in the middle of the night. [Previous page](https://boards.straightdope.com/t/why-do-traditional-japanese-homes-use-sleeping-floor-mats/1026967.md?page=3)