What We Can Learn from Japanese Prefab Homes
dwell.com
dwell.com
Japanese homes have very few windows and those they have are for light rather than looking out. Japanese are very conscious of their privacy and are not comfortable with windows that others can see into their homes. Waterfront property with windows is not in demand at all.
My experience of new housing is was that it uses primarily whole wood that is visible in the finished structure rather than engineered wood or framing that would be covered with plaster or gyp rock and paint in the finished home.
Japanese homes are often drafty which is ok because they are not heated through out but usually have a kotatsu to heat the occupants locally. This works well enough for heat in winter but not as well with air conditioning in summer which are a killer in most cities.
Most houses have dark gray or dark brown exteriors but one in a thousand will be bright yellow. What's with that?
> Most houses have dark gray or dark brown exteriors but one in a thousand will be bright yellow. What's with that?
This is so really depressing. Here in the north most days are cloudy, even in summer, so in addition to the lack of light and the sky being gray, the land is also gray. I have even seen black houses, what's wrong with them.
other reasons that resale homes are not very good business in Japan:
- Japanese believe it's not clean to buy a home others lived in before, they obsess over ultra-modern brand-new places the same way Apple fans like their newest gadget.
- houses fully depreciate in 2-3 decades
- ghosts (this is not a joke. it includes the believe that the house isn't just an object but has a "soul" (this believe extends to cars and other inanimate objects))
See also https://holdblog.com/resale-homes-are-not-a-good-business-in...
* roughly a third of private homes are build like this
* prices are a little lower than custom build (although not as much as when you start the planning)
* very extensive customization is possible
* walls are high tech versions of a century old building technique (wooden frame with heat preserving insulation)
* energy efficiency (walls, heating system, solar) is brought to an extreme
* due to regulations and and extensive planning (Germany, right?) it takes 9-15 months
* The building itself only takes a couple of days
* Building brick by brick wasn't an option to us due to a current lack of qualified crafts men and women (you end up with 90%, waiting months for the rest to be finished)
My thoughts looking at the Japanese ones: Nice minimalistic architecture but some (already mentioned) things seem unhandy. Also doubt that they are as energy efficient as their german counterparts ;)
Not to mention, the homes in this article represent something like 0.01% or less of actual Japanese prefab homes. Most have very few windows, which are very small. The interior spaces tend to be fairly small as well. Not these open styles.
This is all due to earthquake planning. Studies have consistently found lightweight exterior walls with lots of interior support are most likely to remain standing in a severe earthquake. The small windows reduce weight and are also more efficient since the sun in Japan will roast your house in the summer if you have big windows.
If you were tearing down your current house to put up a new one, how much of that would you have to be moved out for?
What I found was very disappointing - costs were the same or higher when compared to a custom unit built in-place, and the options for style, layout, and size were much less.
There is some advantage in speed, but at this size it’s a matter of a few months difference- not enough for the trade offs.
Clayton Homes was in the news earlier this decade for abusive loan practices. They are likely best avoided, and I say this as a Berkshire stockholder.
https://money.com/warren-buffett-berkshire-hathaway-clayton-...
I have been to Omaha for a few shareholders' meetings, and I've toured a Clayton prefab home erected in the convention center.
I do like the aesthetics of the Japanese prefab home that is in the article, but I cannot imagine anyone using the glass shower or tub that open to the entire neighborhood in this picture (to say nothing of having it behind my desk):
https://s3-us-west-2.amazonaws.com/dwell-ugc/photos/60633913...
Glass in the shower needs far too much cleaning anyway, so that really isn't a good idea from several perspectives.
https://www.arredobagno360.it/media/catalog/product/cache/1/...
That's my personal experience :)
Some apartment buildings in China have bathrooms on balconies. Try taking shower in -5C°
As a marketing effort though it makes sense. You can show the whole thing off at a show to someone walking by and anyone who is interested can imagine how it would look with solid walls.
The second floor bathroom is split into two - a toilet on one end of the hallway, a glass shower on the other end made by boxing off the end of the hallway with a sliding-glass door and large windows. Both sets of glass are frosted.
It's clear that the architect used the showers to help with lighting - the side of the building with the showers has the best exposure, and by keeping them translucent all the way into the living space, the hallways, stairs, and master bedroom are bathed in natural light.
Despite the frosted glass, the showers do have a slight exhibitionist feel at first. The second floor shower has a roll-down blind on the outside, primarily for guests.
The third floor shower has partial window treatments, which provides enough privacy given the layout of the neighborhood.
We thought it might be a bit uncomfortable; however, it works out well, and almost all guests have declined to use the blinds. I was surprised too.
If you step up to a higher end manufacturer you end up paying about the price of a site built but with much nicer finishes than the comparable site built. Method, Ideabox, Timberland, etc fall into this category.
It does get easier to address at scale. When applied to construction, the at-scale approach used to increase predictability is primarily available through a) pre-fab construction under conditions approaching control b) repeat buildings, the classic cookie-cutter houses. There's a reason why they're popular with developers.
A custom house will take longer and cost more than the estimate, on average. There is research on this in both small-scale and large-scale construction.
As a personal anecdote, I & partner built our own permanent dwelling (check my posts). It went over time and over budget, and even then, we had to compromise on features.
Don't forget that central heating /AC and "proper" insulation are not a standard feature in Japanese construction. Neither are cellars nor sound-proofing. Their plumbing is rarely winterized, and they often have the classic approach of kitchen on one side of wall, bathroom on the other. That's one bathroom, and a much simpler plumbing setup than multi-units popular in Europe or the US. These are just some factors in a long list that significantly simplify projects in Japan and make pre-fab a strong contender.
The Japanese consumer expects less and pays the same if not more.
A recent Reddit thread of non-Japanese immigrants (I won't link it in case it brings blow back for them) had this (insulation specifically but heating more generally) as the top complaint about living in Japan.
Aluminium window frames… I curse them.
Edit: typo
What? Why?
High embodied energy, terrible insulation, and I don't picture aluminium as a cheap material.
Homes in Hokkaido area, where it gets quite cold in winter, have good insulation. If one is building a custom house in Japan from construction company that does pre-fab, ask to see the catalog for houses in Hokkaido. It will have features such as double paned windows and venting systems with heat exchangers. I'm the only one in the neighborhood with the heat exchanger setup.
Regarding central air versus having a compressor for each room. My previous house in the same area had central air and in hindsight, it wasn't an economical choice. It made all the rooms drafty and we were constantly fighting with low humidity. The current house has it's own compressor for each room and along with the ventilation provided by the heat exchanger, just running two units downstairs is enough for the whole house.
One thing that turned me off property in Germany was the amount of regulation and inspections involved, which can also be a problem in US areas with aggressive localities bent on generating revenue from homeowners. This, in my estimates, increased prices and made home ownership less attractive (for me).
In my pedestrian look-up of prices for homes in Japan, when accounting for salaries, they were comparable in salary-life-years spent, or higher, to US or Europe. What is your experience?
In Japan, I make nearly double what an average salaryman. This made getting a 35 year mortgage possible. I spend about 30% of my income on the home, its taxes, and upkeep. The current house is customized to higher spec then what is typically offered.
Like many places, prices vary quite a bit. This home was purchased during the "before" times and my commute into central Tokyo was between 90 to 120 minutes, by train or bicycle. Land prices is a quarter of what it is close to the center, about half compared to places within an hours commute time. For location reference, my station is: https://en.wikipedia.org/wiki/Haruhino_Station
The building itself is relatively cheap for the quality. I was able to spec it out before it was constructed. Most pre-built houses do skimp on insulation, ventilation systems, and typically have primitive co-generation power.
The curious thing about Japan is that buildings depreciate to zero in 30 years time. Land prices are stagnant or loses value the further out from major metropolitan areas. I had to get a realtor estimate on the house, and in the four years since the house was constructed, I would only be able to sell for about 80% of what I purchased it for.
Define "good insulation". I live in Aomori prefecture and most houses here have terrible insulation, and when I visited Hokkaido it didn't look much better. There is a reason why home centers sell lots of different materials to insulate the house yourself, because the construction itself is awful.
The builders I've worked with; Tokyu Homes and Seksui House build all over Japan and have a catalog of options catered for each region. ie: Kanto (Tokyo area), Tohoku (Aomori), Hokkaido, etc. The contents of the catalog are surprisingly different. For example, triple pane glass and heat exchangers for ventilation is not shown in Kanto catalog.
My ex-partner was an architect and I have a strong interest in things mechanical. Along with experience of having multiple homes built for us and with a western attitude, we were able get a livable house that's fairly efficient (for a Western lifestyle).
Most custom houses should be looked at as custom kits. The standard gives a lot of room for the types of customization people actually want to do, while not a lot of room for the types people do anyway. Round towers look nice, but in practice they waste a lot of space compared to rectangular because nothing fits either inside or outside. (Castles went to round towers when cannons got strong enough to to knock down flat walls, for a while round was enough better in defense as to be worth the downsides)
Prefab doesn't solve that one hundred percent, but I assume it would significantly increase build speed and predictions of completion date.
It's also worth noting that even for a "solved problem", driving down costs is still beneficial in the end.
What is acceptable is an important question. I've been in houses from 100 years ago, most had significant remodels that clearly did things not anticipated originally and so it is obvious to a knowing eye where the different parts are. On the other hand, construction is expensive and the throw away culture seems wrong too. I'll let you decide where the trade off should be made.
Real examples:
I had a gas leak. The pipe was hidden behind all the kitchen cabinets. 1/3 of the cabinets had to be removed to get to the pipe.
At a new build one guy was sloppy and put a nail into a water pipe. The entire wall had to be redone.
You don’t have to save cost if you can increase reliability and speed.
there is, I think, a pretty strong correlation between reliability of a solution and the future maintainability costs being lower.
We did a lot of research and we were initially thinking of prefab for our home, but we finally decided to go for full custom design. In the end, prefab can really make some costs more predictable, at the cost of some flexibility in the design. Cost-wise, it was almost the same (for our case) but construction would've been faster and more probably more controlled in terms of budget.
The land for a SFH inna "sought after area" is at least $300K and probably much more.
https://www.nahbclassic.org/generic.aspx?genericContentID=26...
Here is a developer of prefab houses showing their plus energy house (meaning it produces more energy than it requires to live in): https://www.hanse-haus.de/en/prefabricated-houses/energy-eff... - these are not made out of aerated concrete though, they use timber panels.
Land is quite cheap in many parts of say, Australia or Japan due to low population density, but in big cities the prices increase again.
[1] reviews prefabrication systems, broken down by technology. The conclusion suggests it's difficult for these systems to reach the scale necessary for success.
[2] explains the primacy of balloon frame construction in North America through the frame of "worse is better."
[3] most recently, a survey of componentization technologies.
1: (Two parts) https://constructionphysics.substack.com/p/book-review-indus... and https://constructionphysics.substack.com/p/industrialized-bu...
2: https://constructionphysics.substack.com/p/balloon-framing-i...
3: https://constructionphysics.substack.com/p/building-componen...
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.
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.
Though some Japanese people really want/need a bathtub, so I guess it's just cultural.
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.
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%.
Wait, first shower, then sit in a tub? What is the reason behind this? One or the other by itself should be enough to get clean right?
So the real question would be: Why bathing rather than just showering? It's cultural and it is considered to relaxing and healthy activity.
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.
Something like this
https://i0.wp.com/easylifejapan.com/wp-content/uploads/2019/...
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.
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.
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.
This depends greatly on the crew. Some are more willing to work long hours than others.
European accommodations of similar price category have much worse & more dirty bath facilities in comparison.
I’ve stayed in a lot of fancy hotel rooms, and my single biggest frustration is that my house has a better bath than literally all of them.
Oh well I guess we should be hape we have at least lever control now and not two separate knobs like before.
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)
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.
So in such an environment, innovative / different construction techniques are much more testable and able to be experimented with. And when the costs are being compared against full build, the cost of an even expensive prefab unit is not so bad.
If taxes were 25% and the house was worth 200k and the deceased had 20k in cash, you'd end up paying 55k in taxes but only have 20k in cash to pay it with unless the descendants used their own funds. As such, it's easier to sell the house, take the 220k and pay the taxes.
I mean, sure people are attached to old buildings and monuments, but even those can be rebuilt more or less often.
It's one of those things (like pieces of code) where:
A) You should build often enough that the institutional knowledge and practice can be handed down effectively between generations
or
B) Not build until it breaks and the people doing it have to rediscover and properly design it again from scratch.
It's the dangerous middle ground where people need to modify/rebuild something in the meantime, but lost the practice and knowledge about how to do it properly!
Even shrines and temples are periodically rebuilt. For instance the Ise Grand Shrine (one of the most, maybe even the most important shrine of Japan) was rebuilt in 2015, for the 62nd time...
There was an NHK program I saw recently that interviewed a carpenter who specialized in temple construction (I think he built a store front for a restaurant shown on the program, but I can't find it). I was wondering how that could ever be enough work to live off of. But now it makes sense.
So there would be greater economic demand to rebuild/churn the housing stock.
For most people the cost of the building is enough that if it is functional you would want to use it.
* built on-site vs. fabricated in (usually) a big woodworking shop
* built according to an off-the-rack architectural design vs. built to the architect and clients' desires
* finished with standard materials (on site) vs. finished with custom floors, kitchen cabinets, paints, triple glazing, whatever (on site)
* completely built (modular) units that are just moved into place -- rare, but it exists, e.g. container homes
For residential construction, as far as I can tell there aren't really any cost savings associated with remote fabrication, but the house might be up faster, quality control is a bit better and foul weather is less likely to mess with the schedule. However, it's completely custom, with no limitations whatsoever. The shell itself might be prefab, but it will be finished on-site with a brick facade or render or wood boards or, heck, quarried stone if you like.
Using a standard design as well as the builder's default choice for your tiles, cabinets, toilets, what have you, will save money because these "start to finish" builders (or sometimes general contractors) buy in bulk and pass on some of the savings, but the more you want to customize, the less you save.
The article talks about a very specific kind of prefab that is highly standardized but where nevertheless even the floor plans can be customized, albeit limited to certain standardized sizes and a small set of options, sort of like how you buy a car.
it's not always clear if thermal performance/efficiency will be better, and they usually are very expensive. they might be cheaper than building a 700 square meters house, but that doesn't help a lot people looking for 70 square meters homes.
meh.
[1] : https://www.theguardian.com/cities/2017/nov/16/japan-reusabl...
It’s not the same wealth as having $500k in cash or investments, as you always need a roof over your head. It’s not nothing either, as you might be able to sell and move somewhere cheaper, but that’s costing you in maybe moving somewhere you don’t want to be.
The “wealth” of being in a $400k house that goes up to $500k isn’t all that great when the house you were aiming to move into goes from $500k to $700k.
It just seems so obvious that it should be cheaper to do as much work in a factory as possible. Home construction seems like one of the few large industries still stuck in the time before the Industrial Revolution: work done by hand by a variety of highly-skilled artisans instead of mass-produced at scale.
Land isn’t the main driver of cost (unless you’re in one of a handful of ultra-desirable locations). Nor is the sitework or the foundation. From a few quick sources, it seems like the structural and finishing work (everything starting with a slab and ending with a finished house) is roughly 80% of the cost. This is exactly the part that seems like it could be done in a factory with a high degree of automation, like with cars and furniture and most manufactured goods.
What am I missing here?
I am having a new home built right now, and the costs are roughly 50% for the 'shell', e.g. to the level where you have a water proof building with roof and windows, and 50% for all the work inside. For the 'shell' it's actually quite simple work, and doesn't take too much time, it's basically just LEGO :D The complicated parts like doors and windows are made off-site, so when they arrive you just need to fit the house around them. We are having a traditional A-style roof, so the roof joists are made off site too. Most of the costs are on the materials, not the work. Materials that reduce the work like ICF or SIPPs also increase the material costs - in my case to a point greater than what you save in labour costs.
For the interiors nothing can really be prefabricated at volume, as everything is completely custom to the project. That's not going to change unless these Japanese standard measurements that article talks about spread elsewhere. For large projects its a bit different though, I've heard for hotels they sometimes prefabricate large parts of the bathroom and lift it into place before the next floor is put on. That makes sense though as you are building a few hundred things that are exactly the same.
Because it's priced to match non-prefab.
What is done on site are things that people want to customize, and so there isn't must opportunity to standardize other than to make all houses the same which people don't like.
Assembling of one of them in a day: https://www.youtube.com/watch?v=f4ndJF64M3I
https://en.wikipedia.org/wiki/Kotatsu
Even these days it's common to use gas heaters that are turned off for the night, meaning that it's freezing cold particularly in the mornings.
Building Foundation Buying Land Electric, water, sewer.
So prefab only gets you so much.
i don't understand this pseudo fascination for japan
also, it solves nothing, it is an excuse to not focus on the real problem
the housing market and the insane amount of speculation around it
But I agree that prefabs aren't particularly interesting.
Or is the catch that they're so cheaply built that you don't want to live in them?
Yes, or at least they'll need a big refurb.
I highly doubt that "designing for it" really beats inherently stronger building materials to specifically choose wood with its many, many other disadvantages over something else.
There is a reason Japan traditionally used wood, it works well in general. The design for it parts of wood are not hard - I don't know Japanese history, but I'd guess they figured it out well B.C.
You don't need to flex, and dissipate energy if you can simply withstand earthquake G forces through strength alone. And even if you do, steel is obviously better at energy dissipation.
It makes “commute until you qualify” longer than it might otherwise be. And it doesn’t help that there has long been a tendency to overcentralize in Tokyo, which is very large and can take a while to commute around.
If you were going to take any lessons from Japan regarding housing, wouldn't it be more along the lines of how to build high density housing cost effectively in coordination with world class public transportation infrastructure?
What is the average temp swing per year in Japan? Like a 40 degree (F) swing over the year? Lol, ok, show me those amazing looking modern prefabs for places there you get 60 degree (F) swing in day and let’s see how they’re doing. Or that cool aluminum place with 2ft of snow on it. Etc.
Not that we can’t learn lessons, but I think structures just need a lot less engineering in Asia compared to other places.
That's an odd assertion. Why do you think that Asia, a massive continent with literally billions of people and wildly varying climates and terrains across it, needs less engineering of structures than other places?
Edit to add that I'm not saying wood is bad. I love wood houses.
Because they are so popular, they are even less expensive- construction crews experienced in building double brick walls are scarce to non existent around here.
On a final note, tornados. We get quite a few of them around here... The odds of actually being hit by one are low, and yet it does happen, and I doubt brick walls would hold up much better facing the full fury of those.
A quick search would've saved you all those rightful downvotes.
There are many German and Dutch companies that make high-end pre-fabricated houses and walls that sell not only locally, but abroad.
Many factors contribute to the purchasing decisions of quality pre-fabricated housing materials, of which price is only one (and probably isn't even a factor at the high-end).
> the housing market and the insane amount of speculation around it
Couldn't agree more.
> i don't understand this pseudo fascination for japan
Because people who've not lived there usually have entirely the wrong idea about it, and articles like this one with its buzzwords (the first paragraph is almost parody) and lack of context (number one would be the low quality of housing in Japan, it'd be literally criminal if anyone with the power to look into it would), add in a mix of (seemingly) impenetrable language, stereotypes from the 1980s about futuristic technology, and endless animes about robots deepening that, and you end up at "wow, Japan!"
Meanwhile, I freeze my arse off every winter and curse the build quality daily.