Reinforced Concrete Homes - the answer to the question we're all asking???

[tre]

Hello,

I've been looking into buying a house for the last little while, but am consistently befuddled at how absurd the prospect of buying a house with a 20- or 30-year mortgage, only to have the house worth nothing at the end of that time. The flimsy wood-frame homes that are commonplace come off as the worst housing option thinkable. After doing more and more research, I've found that reinforced concrete homes are growing in popularity and dropping in price. Though there are none in my part of Sapporo yet, they are popping up in the more trendy parts of town. I can't help but think anyone who doesn't start building RC is foolish. Some companies even include a 60-year warrantee. They stay warmer in the winters and are more energy efficient, are just slightly more expensive to build (we're talking 2500万円 for wood vs. 3000万円 for RC), last doubly as long, and are way stronger in earthquakes. They're also more customizable because there are no crucial support beams necessary in the inner walls because the outer shell is so strong.

Additionally, mansions around here have been RC for a long time, and are in much higher demand than wooden ones. Why not have your own RC house?

Does anyone have any experience living in or working with RC? Are there any downsides!?

Thanks in advance!

[TJrandom]

...Does anyone have any experience living in or working with RC? Are there any downsides!?

Thanks in advance!

No experience here in Japan - but have built a "walk-out" livable basement home in the US. Downsides – IMO….

Uuuugly
Impossible to modify the floor plan
Cannot pull new electrical, plumbing
Colder and more expensive to heat in the winter if good insulation is not used (off-set in the summer if the S side is shaded)
Cannot easily obtain large rooms (costly steel beams may make it achievable)
Hard on your skeleton (unless you raise a wooden floor on top of the concrete)
Does indeed crack – and if it does it is impossible to repair
Holds moisture – causing any raised wood flooring, wall coverings, etc. to be suceptical to rot and mildew
More expensive to build and much more expensive to remove
You had better be watching and testing as it is being built – or the builders will reduce reinforcing steel and use a poorer concrete mixture. (I’d have an independent inspector/tester – and a hefty contractual fine in place – since you will live with whatever has been built – since the test results come days AFTER it is too late to make corrections.)

[tre]

No experience here in Japan - but have built a "walk-out" livable basement home in the US. Downsides – IMO….

Uuuugly
Impossible to modify the floor plan
Cannot pull new electrical, plumbing
Colder and more expensive to heat in the winter if good insulation is not used (off-set in the summer if the S side is shaded)
Cannot easily obtain large rooms (costly steel beams may make it achievable)
Hard on your skeleton (unless you raise a wooden floor on top of the concrete)
Does indeed crack – and if it does it is impossible to repair
Holds moisture – causing any raised wood flooring, wall coverings, etc. to be suceptical to rot and mildew
More expensive to build and much more expensive to remove
You had better be watching and testing as it is being built – or the builders will reduce reinforcing steel and use a poorer concrete mixture. (I’d have an independent inspector/tester – and a hefty contractual fine in place – since you will live with whatever has been built – since the test results come days AFTER it is too late to make corrections.)

TJRandom,

Thanks for your reply!

I should have included some links in the original thread to show you some pics (granted these are CG mockups...the real ones look similar!):
http://www.dhome.jp/bukken/sale022.html
http://www.palcon.jp/product/design-...dex.html#modan

IMHO, styling is all in the eye of the beholder. But compared to just about any other houses up here in Sapporo, these houses are BEAUTIFUL. Though I have seen some naked-concrete buildings (ie, no paint or tiles or finishing) that look like garbage after about 10 years because they weren't cleaned.

As far as the floorplan modification, almost every builder has mentioned that, because the walls and floors are all wood, it's actually easier to modify the floorplan. And if you're building from scratch, you can just give them specific instructions on how you want things to be shaped in the first place anyways. (A problem we're having is that we want a 5LDK, but there are VERY FEW decent houses that are more than 4LDK! Though the first link listed above has a 5LDK, which I love.)

Regarding insulation, yes there is a good deal of variation in the builders we've been looking at. Some simply spray on an insulation layer before putting in the drywall. Some install a "board" of insulation seperate from the concrete before putting up the drywall. There are also different ways of actually setting the concrete so that bubbles and airpockets are minimized. Thanks for your input on this, as I wasn't putting much weight on it.

Compared with wooden structures, large rooms are actually easier to build because of the lack of necessary support beams. Though the largest room in the house we're looking at is only like 20帖 anyways, so that's not a big deal.

Good call on the bodily damage factor. Some builders build a proper wood floor on each level, giving it that warm, supportive feeling. My parent's house in Los Angeles has a straight up concrete floor, so I know what you mean when you say this!

Cracking - yes, they have high requirements for how strong the land is that they build on. Looked into this, and apparently you cannot build RC on just any plot of land, even if there was a wood-frame house there before. The foundation must be next to invincible to prevent the house from shifting and causing cracks. Then again, with those companies that provide a 60-year warrantee, perhaps things like this are covered....That's something to look into.

Moisture - Most companies boast of their higher-tech ventilation that RC allows. Apparently you can have continuous ventilation without losing warmth in the summer. Some builders have mentioned that yes, you will need to squeegee the windows once in a while in the winter, though one company showed their ventilation system that actually recirculates the air through the (concrete) floors and walls to warm the entire house.

Another good call on keeping an eye on them as they build. I know almost nothing about building or the details of rebar or concrete. I wonder if I could do like you did and get some kind of independent contractor in place to overlook and make sure everything is right on the money.

Thanks again man!

[hml]

You've covered the pluses and minuses pretty well I think. Consider this option too:

http://www.dome-house.jp/case/index.html

Ultralight weight, strong, virtually earthquake proof, and if it does fall down, the structure itself would not be enough to kill you.

downside: you have to go bare-footed, smoke a pipe and wear an invisibility ring.

[TJrandom]

If you are serious - I'd suggest this...

go to a builder's trade show and ask around and then weigh that information. Get your invite from a builder or builders supply shop.
take a close look at the results (homes your potential builder completed 5 to 10 years ago) and speak with their owners.

It seems that your internal walls, and ceiling/floor are wood – not RC, and maybe only the exterior walls, roof, and first floor are RC. That should give more flexibility.

I’d be careful on external siding/covering. Since the inside will be covered, you will not be able to detect cracks if they occur.

Also – a flat roof is an eventual leaker, so I’d make sure that it is well sloped and has good plumbed drainage for rain and snow melt.

[Chromedome]

Steel framed Sekisui Heim are pretty good... mine's six years old now....and it should be fine for another 100 or so....

Concrete joins tend to expand and contract a lot and can be noisy at night when the house is cooling off...

[TJrandom]

I looked at those floor plans – and while they are probably appropriate for young families who want to live inner-city, they would not be appropriate if someone becomes immobile, requires a wheel chair, etc. If I were going three-story, I’d put in an elevator. At 60+, I want to be able to be all on one floor – full LDK bath, toilet and bedroom, with any additional floors there for use by guests.

[tre]

Steel framed Sekisui Heim are pretty good... mine's six years old now....and it should be fine for another 100 or so....

Concrete joins tend to expand and contract a lot and can be noisy at night when the house is cooling off...

Chromedome, tell me more about your house. I haven't actually talked to anyone with a steel-frame house, I've just heard some small facts that automatically kind of deflected my interest over to RC. One is that the steel, if it's exposed, will eventually rust. The other is that the "official, government recommended lifespan" is less than RC. I think it was something like this:
-Wood-frame : 27 yrs
-Steel-frame : 37 yrs
-RC : 47 yrs
Or thereabouts. Any other links or anything you can provide would be helpful!

[tre]

I looked at those floor plans – and while they are probably appropriate for young families who want to live inner-city, they would not be appropriate if someone becomes immobile, requires a wheel chair, etc. If I were going three-story, I’d put in an elevator. At 60+, I want to be able to be all on one floor – full LDK bath, toilet and bedroom, with any additional floors there for use by guests.

Yeah TJ, I agree that it would suck for older people. As of now, we're still childless and quite young. As mentioned earlier, we're looking to buy a lot that is WAY bigger than the house we plan to build, and that will give us flexibility to do one or many of the following:
-rent out parking / storage
-build a smaller building should my business grow
-build a smaller building should one or more of our parents want to come live with us sometime down the road (10+ yrs away!)
-basketball court and/or trampoline

Though some builders have a simple plug-and-play elevator option for something like 20万円, it is something to consider.

[tre]

Another interesting thing that's kind-of on this topic, is that a lot of these RC home builders are including new, higher-tech energy saving tools in their packages. As we all know, the threat of energy prices going up in Japan is on the horizon, due to the shutdown of many nuclear plants, so I'm particularly interested in this!

One of the links above includes solar panels on the roof. The brochure mentions that they will lower your energy bill up to 13万円 per year, which is significant. I did some research on how snowy climates affect the efficiency of solar panels, and even in very snowy places like Canada, people are starting to use them. If they are covered by snow, they lose efficiency, so staying on top of that is important, but even if you just let them be covered in snow, they apparently can more than cover your electric bills in the sunnier summer months. With the right setup, you can sell energy back to the city too.

Another model home we saw had a system whereby a generator out back of the house uses natural gas to create energy for you to use and power your heating system. According to their graph, as a result, the cost of your entire energy bill in the winter months drops lower than it is in the summer months because the system provides much more kWH per yen than normal electric systems.

Perhaps this merits it's own entire thread!

-Another bonus question: ALL DENKA. Some hail it as the new healthy, safe, fad. My wife hates the stoves (as in, where you cook) that are denka because she's heard they are less healthy than normal gas-powered fires. And with the energy prices potentially about to go up, perhaps All-Denka loses it's edge. What are your thoughts?

[Koenji]

I've heard that insulating is not so good with concrete. With wooden houses, you have the air spaces in the walls where highly efficient fiberglass insulation drops right in. Sealing a wooden house over the ceiling etc. also is cheaper and easier than with concrete.

The problem is isn't wooden construction, per say. Rather, it's the Japanese attitude toward housing construction in general.

[hml]

The problem is isn't wooden construction, per say. Rather, it's the Japanese attitude toward housing construction in general.

Could be said about a broad range of topics regarding Japan...

[TJrandom]

...including new, higher-tech energy saving tools ... solar panels ... ALL DENKA. ... less healthy?

We have an all electric kitchen - and had never considered it to be any less healthy. It is cleaner than gas (no gas fumes).

If you are not concerned over the price tag, by all means - I'd go all electric - but also have a backup that does not require grid electricity. This could be oil space heaters or solar. But if you are going to be paying an interest rate - then you should be very carefully evaluating the costs of everything. For Hokkaido - I'd go heavy on insulation and any other energy saving items - but discount just a bit what the sellers are telling you.

I do not believe that they have a moral objection to lying - and the legal system is not likely to back you up if calculations are off. Also - check that they are actually building the home that they have received architectural certification for - as builders will always cut corners if it saves them effort or cash. This means frequent site inspections from an interested third party that knows what to look for.

[tre]

TJRandom,

Thanks again for that reminder...I agree that it appears that most salesmen (for anything) have no moral objection to lying in Japan. (Same could probably be said in most countries tho!)

As for the gas vs. electric range issue. Apparently electric ranges cook using infrared radiation, which, according to my wife, is similar to microwaving all your food, all the time. Yeah, gas ranges are more dangerous because of the leak factor, but she hates the thought of microwaving all her food too.

[YokohamaTommy]

I wonder if you could build a Geodome.

Not very expensive.
More space for your buck.
Modular. (easy to add things later)
Can build partially underground.
The frame can be DIY.
Looks cool as hell.

And most importantly, it won't fall over in an Earthquake.
Not sure if it floats, though.

[tre]

I wonder if you could build a Geodome.

Not very expensive.
More space for your buck.
Modular. (easy to add things later)
Can build partially underground.
The frame can be DIY.
Looks cool as hell.

And most importantly, it won't fall over in an Earthquake.
Not sure if it floats, though.

Those look sweet, but I think I'm a little too OCD to deal with the wasted triangles of space behind all of my square furniture

[NorthByNorthwest]

This stuff is technically concrete, but without all the disadvantages:

http://en.wikipedia.org/wiki/Autocla...rated_concrete

[tre]

Went to go check out this house:

but it turns out it's not even finished yet. So I walked around the contruction site and peeked in. It all looked quite good. So we did the next best thing and went to check out the company's "Flagship" house and talk with a sales rep.

Here's the "Flagship":

http://www.dhome.jp/bukken/sale019.html

It was an interesting house, though it was actually surprisingly small with a lot of wasted space. (Keep in mind that the car in front is not an FJ like the other house, but an SC430 )

The company seemed surprisingly unflexible, though the salesman answered our questions well. Turns out the additional tax for building concrete is about $600 per year, and that gradually decreases over the next 47 years. The biggest piece of info he shared with us, is that our side of the city apparently has "soft" soil, and if we wanted to build a concrete house, it might end up costing $texas to properly prepare the ground.

He said that concrete houses are 10's or 100's times heavier than equivalent wood-frame houses, so they have to be picky about the soil. Also explains why there are none that we can find on this side of town.

He answered a bunch of other questions about roof drainage and sealing, which all seemed good. That particular company's warrantee for their workmanship was only 10 years, which seems surprisingly low (and is in fact, the minimum required by law).

So our next step is to get in contact with some other companies and see what they can do. Another one (Ube House) mentioned that they can help us find suitable land, and in their catalog, every house they listed, though fairly priced, was designed according to the owner's needs, which is neat. The company we talked with today basically said "4 rooms is the most you can get, so stop asking". Oh yeah, and they said "All denka, or take a hike." too.

So the search continues.

[TJrandom]

Another caution here... when the plumbing is engineered - make sure that you specify that the supplies (both hot and cold) be run in conduit - and not have the pipes imbedded directly in concrete. That way they can be replaced if needed, and not require external routing (ugly) or structural damage to get to them. As the supplies are under pressure - any leak, no matter how small - will require replacement. The drains are not such a problem - as they gravity slope.

They use flexible supply pipes these days - so running in conduit is important for a second reason. They sag if not supported, and inside concrete - when it is poured - they will tend to sag even more when pushed by the wet concrete. Any sags that hold water will be places that will freeze and break - should you ever be away and not keep the place heated (or with an extended power outage). Thus the conduit should be installed as if it is is a drain - with built in slope. Thus - when the house supply is disconnected at the meter (lowest point) - or when a bleeder valve is used at the meter - and with all faucets opened - all supply pipes should naturally drain.

[Koenji]

He said that concrete houses are 10's or 100's times heavier than equivalent wood-frame houses, so they have to be picky about the soil.

I'm no expert, but wouldn't building a basement help solve this issue?

BTW, do those places have roof-top decks? I can't understand why Japanese houses waste so much potential space, given the high price of land here and how crammed most interiors are.

[thefg]

downside: you have to go bare-footed, smoke a pipe and wear an invisibility ring.

so no change there then

[tre]

I'm no expert, but wouldn't building a basement help solve this issue?

BTW, do those places have roof-top decks? I can't understand why Japanese houses waste so much potential space, given the high price of land here and how crammed most interiors are.

Yeah, I've kinda wondered why people don't have basements....Sometimes you see these half-in-the-ground garages and stuff, but the downside to that in Hokkaido is that when it snows 2 feet in one night, you're shoveling uphill for 3 hours to get your car out. In terms of just having a basement, I don't know why they don't have them...perhaps the threat of gargantuan earthquakes keeps them at bay.

Many of the concrete houses we've seen have rooftop decks, but almost none of the wood-frame or steel-frame houses do, though they have normal balconies coming off the second floor.

[Japan.bound]

Are any of these dome houses already built for sale in or close to Tokyo? Is owning a home a viable option before I acquire permanent residence, or should I hold off on buying one until I establish PR?

[tre]

Are any of these dome houses already built for sale in or close to Tokyo? Is owning a home a viable option before I acquire permanent residence, or should I hold off on buying one until I establish PR?

I've never seen them...

As for having property, anyone can own in Japan, it just won't help you get PR. I'm not a PR yet, but I'm married to a Japanese woman and we plan to be here for a while.