I’m not sure what to take from this. In all my 8 years of living in Japan I have yet to see any prefabricated homes being built (and I’ve probably seen hundreds of houses under construction).
Even the most budget builder, say your prefecture's Co-op builder, will use pre cut framing. Our builder, Hinokiya, used factory built frame pieces.
The article's photos of prebuilts is misleading. The majority of prebuilding in Japan is about factory built framing, precut beams, and unit baths. You'll not notice these homes, because they look the same as everything else.
More over: most homes have something prebuilt. Near every bath in every home is a unit bath.
My definition of "unit bath" must be different than yours. A unit bath for me is something I find in a small single room apartment in Japan. It's got the sink, tub, and toilet in the same room almost all entirely molded from one piece.
AFAIK that is not the norm in Japanese houses. A house would like have a toilet in one room, sink in separate room, bath in a 3rd room, and that bath is is about the size of 2 American bathtubs. One area of the tub, and one for watching (a wet floor).
AFAIK that's the norm in a Japanese "house" as well as most modern 2 bedroom or larger apartments. Smaller and/or older places have a "unit bath" (I lived with one for 6 years but my current place has everything separate)
A lot of apartments and houses were built in the area where I used to live in Japan (and will, again, when we can travel again). So I got to see the progress every morning when I walked the dog. As far as I could tell nearly all the new houses and apartments got their bathrooms as a "unit bath", there would be a truck parked nearby and the bath transported as a unit directly from the truck and brought inside.
Talking about prefab, it's supposed to go faster (and that's normally the case), and time is money (more or less so, depending on where you live), but in Japan I once saw a two-story eight-apartment building being raised and completed in less than 7 weeks. Not prefab, not completely anyway - they obviously used modules where the could. But you could still see walls etc. being built the "normal" way.
It was built on what used to be a field, I walked past it every morning when walking the dog. First they put up the (now mandatory I believe) steel framing, then they continued building it piece-by-piece. Floors, wall, roof, solar panels on the roof, doors, windows, plumbing, air conditioners/heating, painted tarmac parking area outside (with two allotted spaces for each apartment), a little roofed area to park bicycles, garbage bin area (again roofed), and cleanup. Less than seven weeks. It's the most astonishing thing I've ever seen when it comes to building not being fully prefab (the exception was the baths - they were installed as units). During the same period a slightly larger apartment building was set up in my home country, near my home there, it took nearly two years and when they were finished it still looked shabby and unfinished outside - no tarmac, no grass, leftover stuff everywhere. Took forever to get that cleaned up.
So, why did it go so extremely fast in Japan? Logistics. Everything arrived on site exactly when it should. Nothing stopped. When stuff for the roof arrived there was already a conveyor belt set up to transport it up to where it was needed. Nobody had to wait for someone else to finish what they were doing. Nothing stopped. They worked Saturdays too, but they didn't work evenings. It was just all incredibly efficient. The someone who worked out the logistics for that project.. I've never seen anything like it.
My first apartment was that kind of unit bath, but my current apartment has a separate sink and toilet, but the bath is definitely one manufactured piece of plastic that contains the full shower area; my wife's mom's house, and my friend's house are both the same, so I figure it's pretty common.
The prefab baths (at least those in Japanese hostels) are superb! Basically no seams where dirt could accumulate and mold grow, robust ergonomic and well thought out furnishings, splashproof doors and lighting.
European accommodations of similar price category have much worse & more dirty bath facilities in comparison.
Does factory built frame pieces mean like pre assembled walls? I watch a lot of construction youtube and timber is generally pre cut and trusses pre assembled so I can’t see how it would speed up much.
Having been in construction site works longer in many cases. When the tradesman has to travel 1 hour to the site, he is going to want to work long hours to get done sooner. (2 12 hours days is = 3 8 hour days). We worked that job because we knew if we refused the builder would find someone else who would - and then we wouldn't get the jobs closer to home either.
This depends greatly on the crew. Some are more willing to work long hours than others.
Is there a catch here? Do these homes have everything you'd expect from a normal home? Like utilities/heating/ventilation/earthquake safety/etc.? What do they compromise on?
The video is showing a metal "lego" form of prefab. These are limited to the premium home builders. Habel, Sekisui, Sumitomo etc. These homes are metal centric, and thus more expensive than wood centric homes.
There are plenty of wooden pre-fab homes, but those center upon pre-cut timbers or other factory manufacturering. Only metal can do the rooms-as-lego-pieces style.
I guess it depends on where you live. I've been in Japan about 20+ years... in the "countryside" I never saw them being built, but here in Shizuoka you see them a lot. Personally, I'd never waste my money on them... the one's I've seen use really cheap materials for walls and doors. I could probably fall THROUGH a door if I tripped...
I've lived in Tokyo for 2 years now and see prefab homes popping up practically nonstop, from makers like Hebel House and Sekisui; and if you walk around any neighborhood it's not hard to spot the seams in the majority of houses, where panels and modules slot in and out.
I suppose for appartments unit baths are prefab? Like just a sealed block with your toilet and bathtub, all in one package.
There's also just like... the shower room itself, even in nicer appartments, that ends up just being a block (see video of installation). Seems like a pretty good way of reducing issues like leaks or weird plumbing issues.
> the shower room itself, even in nicer appartments, that ends up just being a block
These are the best! One of my favorite parts of Japanese apartments. They make so much more sense than standing in a narrow bathtub, next to a toilet, in a room where you can't splash water everywhere.
With that being said, I'll take the insulation and central heating/cooling from western housing.
I live in Japan as well and this it the thing I hate the most! You have half a shower and half a bathtub (unless you go very high end). I'd rather prefer a full shower or a full bathtub instead. Same happens with the toilet, it's a claustrophobic "room" under 1 sqmt, smaller than a ryanair seat. I would strongly prefer either having a bigger shower (no bathtub) + bigger toilet, or a bigger bathtub (no shower floor) + bigger toilet!
Though some Japanese people really want/need a bathtub, so I guess it's just cultural.
Shower + bathtub style is unacceptable for traditional Japanese lifestyle. All people on family take a bath everyday after a shower. They shares same bath water on a day because replacing water on a bath every time is huge waste of water and energy.
It's fine for single person who don't take a bath but just a shower, but it seems to not majority.
Most Japanese hates shower/bathtub + toilet style because it seems to completely nonsense, small space is relatively not a problem. While bathing, why should we see toilet and sniff toilet smell? Also toilet paper and cloths wets by bath. It's more problem for a family because Japanese house very rarely has multiple shower rooms.
Yes, I understand that the dynamics might be different for a family. In Spain normally you'd have 1 bathroom for each 1-2 rooms, so a house/appt with 3 rooms would normally have 2 bathrooms.
I am talking mainly as a single person renting. And of course it's my opinion coming from a different culture.
"While bathing, why should we see toilet" I prefer to see an ample room while doing anything, than to have a wall right in front of me. It's not about the contents of the room, but about having walls less than 1 feet on each side of my face (for the toilet). "Toilet smell" should not be a problem normally with decent ventilation, specially with the industrial fans that Japanese homes seem to have in the bathrooms.
My issue is with overall distribution, where Japanese houses (at least for single person/room) seem to take 30~40% of the floorplan space in what in other countries would be a single room taking 15~20%.
As the others said - you get clean in the shower (or, traditionally, by sitting on a stool and washing yourself with water taken from the tub - not a tub really, a round or square relatively deep bath). When you're as clean as can be you sink your body into a very hot bath. With modern baths you can set the temperature to be exactly what you want. I'm fine with 41C, my wife (as can most Japanese) can manage hotter water and prefers at least 42C except in the summer - cooler is better then.
The long hot bath every evening is vital.. Japanese houses are cold in the winter. No insulation, no bedroom heating, barely above freezing. If I don't take a bath at night I'll be so cold that I'll have trouble sleeping. But after a long bath I'm fine. Not feeling the cold at all and this lasts all night. Seems to help with my health too. No pains, colds are rare. Very much unlike like now, when I'm in my home country waiting for travels to open again.
The tub is for relaxing. The wash area is for washing. The Japanese tradition is first wash outside the tub. When you clean, climb in the tub and relax (like a Jacuzzi)
You don't have to go "very" high end. Nearly everyone I know who isn't under 35 lives in a 2 bedroom apartment with a tub larger than most western tubs and a shower (wash area) which just as much space as that tub
That's tub is the same length and wider than any of the 25 places I've lived in the USA and the shower would just be an attachment in the tub and I wouldn't have the wash area next to the tub.
