Building Culture: Differences between Japan and the UK

Different countries have different building cultures, and the differences between Japan and the UK are immediately visible. Just like the buildings themselves, some of these differences are superficial and others are structural, some are easily visible and others are buried and hidden deep underground but have profound influences.

In Japan people like new houses but in the UK people like old houses. I think this comes from the fundamental difference that in the UK houses represent capital wealth, while in Japan the value is in the land, and houses are consumables. Before we decided to build, we spent a few years looking at buying a house, and visited many that were unsatisfactory, in one way or another. A few times we noticed houses for sale moving into the list plots of land for sale, as the building was knocked down. In these cases, the price usually went up, suggesting that an old building on a piece of land is a liability and the land becomes more valuable when it is removed.

In the UK, if people want a different house, they will sell up, buy a new one and move. In Japan they will knock the house down and rebuild. Redecoration and renovation are carried out on a regular basis on UK houses, while in Japan they are more of a recent trend.

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'A masterpiece': Norwich council houses win Stirling architecture prize

From the guardian: https://www.theguardian.com/artanddesign/2019/oct/08/stirling-prize-architecture-goldsmith-street-norwich-council-houses

It looks like the windows are slightly tilted from the vertical to increase solar gain. 

Squaring the Circle for Traditional Buildings

It often seems that there is a battle going on between traditional building techniques and high-insulation high-airtightness approaches such as Passive House. Advocates and practitioners of traditional buildings have a strong case that years of experience will show how and when buildings fail, and how they can be built to last. They claim natural materials can absorb and release moisture and are free from dangerous chemicals, so they are better for the building and more healthy for the inhabitants.

But traditional buildings do not use a lot of insulation and are not airtight, so here are two questions: 

How do you keep a traditional Japanese building warm in the winter? 

How does ventilation work in traditional Japanese buildings to ensure good air quality?

I'll get to the answers soon.

High airtightness is sometimes achieved with synthetic membranes, but concrete, plaster on stone or brick, and oriented strand board (OSB) can also play a part in a building's airtight layer. Insulation materials are often polymer-based, especially where a high performance is needed. To get the same insulation as ten centimetres of top-grade foam, you need over 30 centimetres of thatch, over 80 centimetres of wood, a similar thickness of clay mixed with straw, or over two metres of rammed earth. Cellulose fibre insulation is better than all those traditional alternatives, but you would still need over twice the thickness to match foam.

It is interesting to note that a mixture of clay and straw has a similar insulation level to wood, which means that a structure of wooden posts and pillars filled with traditional walls may have an even layer of insulation, avoiding cold spots. But a typical passive house wall has something like ten times higher insulation than a traditionally-built house, so for those walls to perform in the same way, they would need to be ten times thicker.

So how do you keep a traditional Japanese building warm in the winter?
Short answer: You don't. 

When it's cold outside, it gets cold inside. The walls are porous so moisture does not tend to build up. If you want the house to be warm you have to start burning stuff. Today that stuff is usually fossil fuel, either directly, or indirectly with electricity generated from fossil fuels. So you certainly can build with traditional, natural materials, but the inhabitants are only going to be comfortable with a steady flow of un-traditional, unnatural fossil fuels. 

Traditional Japanese heating is with wood burnt in an irori open fire or charcoal smouldering under a kotatsu table heater. Irori are open fireplaces in the middle of the room. Traditional Japanese buildings don't have chimneys, so the smoke finds its way up though the house, killing any bugs on the way, and then out through the ample gaps in the structure.

Traditonal kotatsu burn charcoal in a small irori pit, with a table over the top covered in quilts and blankets. The kotatsu just provides a warm space to sit in rather than warming the whole building, which in some ways is a very efficient use of fuel. This 1820 woodblock by Eisen Keisai also hints at other ways couples kept warm on long winter nights. 

Today people do not want open fires because of the risk of the house burning down, and the increased soot and extra cleaning. Charcoal-burning kotatsu are also a carbon monoxide risk so modern kotatsu use electric heating elements. They are still occasionally fatal because of the heat shock when elderly people get in or out of them. Many people in Japan love their kotatsu, but if they start living in an insulated house, they do not miss them!

Most Japanese homes do not have any central heating system, often relying on kerosene fan heaters, electric carpets, or air conditioners in heating mode. Some houses have underfloor heating, but there are frequent stories of people who use it for one year, see the electricity bill, then never switch it on again. None of these heating techniques is traditional or natural. 

Wood burning stoves may be a more natural method, and cast iron stoves from New England or the west coast of Ireland do look very nice in Japanese houses. The rituals of preparing wood and the cleaning and maintenance may not suit everyone's lifestyle, the smoke may not please the neighbours, and unless the house is in the middle of a forest the source of wood may not be sustainable. An increase in wood-burning stoves has been blamed for poor air quality in London, and since London is not a major producer of wood, you also have to wonder about the carbon footprint of transporting the fuel. 

Wood pellets are much more efficient than burning wood directly, which not only means less wood, but also less ash to clear from the stove and less pollution going through the chimney. The first wood pellets were made from sawdust waste from timber mills. However, as demand increases, and efficiency leads to less waste, trees need to be specially cut and grown for wood pellets. Economically speaking, pellets may have started off being made from a waste product with zero cost, but as and demand increases, the price may go up. The impact is not zero and while burning wood pellets may be better than burning fossil fuels, they do not provide a solution to the world's energy problems, and whatever you are burning, it's still better to burn less. Ideally some of the trees in our dwindling forests will be left as habitat, and end up falling to the ground and emerging in a few millennia as a carbon source for future inhabitants of the planet. But I may be digressing from the topic of traditional buildings. On the other hand, preservation of the environment may be exactly what advocates of traditional building want. 

If I may return to more urgent matters of survival, when a building is airtight, it must be ventilated. The solution used in most passive houses is a mechanical ventilation system with heat recovery. Advocates of traditional building techniques often have a visceral reaction to the idea of mechanical ventilation as it is clearly not a traditional way to ventilate buildings. It uses electricity, so how could that ever be natural?

It is not natural. But what exactly does "natural" mean? When people call for natural materials, what are they asking for? Asbestos occurs naturally in the ground, but I'm guessing you wouldn't want that in your natural building! Polyethylene and polypropylene are completely synthetic and harmless to taste and touch.

If you really want nature, you should go and live outside. Buildings are not natural. Rather than asking a binary question whether specific materials or techniques are natural or not, we need to look at health, comfort and energy use, over the lifetime of the building and make the least bad decisions to get the best health and most comfort for the least energy use and lowest environmental impact.

So how do you ventilate a traditional building? 

I'm temped to say that you don't, but of course traditional buildings are ventilated—just not in a very systematic way. If there is a fire in the building then it is also working as a ventilation system by sending hot air up and out of the building while drawing air in through those thoughtfully provided gaps and porous surfaces. When there is no fire, air must find its way in and out through open windows and doors. The amount of natural ventilation then depends greatly on the outside temperature, wind speed and direction. So if a house is designed to always have fresh air, it will usually have too much ventilation. This will lead to uncomfortable drafts and a steady loss of heat. If it is designed to minimise drafts and heat loss, then there won't be enough ventilation for good air quality and control of moisture. 

The traditional builders will usually choose too much ventilation because that is the only way to guarantee there will be no moisture build up. So the house should not be airtight. If the builders do make the house airtight, they need to put in mechanical ventilation. They could ensure ventilation by providing a fire for you to keep stoked, but if they do that, they need to make sure there is no risk of carbon monoxide poisoning, which again will probably mean avoiding airtightness.

Mechanical ventilation does use electricity, but it provides fresh air, takes excess humidity out of the house, and keeps you warm very cheaply by recovering the heat from the expelled air. Heat recovery ventilation will only work if a building is airtight, making sure that air is coming in and out through the heat exchanger. Also, the insulation will only work effectively and without risk of condensation within the walls if the building is airtight. And if the building is airtight, active ventilation is needed because natural ventilation is unreliable.

Without active ventilation and airtightness, extra insulation is a risk as air leaking out of the house in winter drops in temperature and hits the dew point, producing condensation.

So the traditional builders are going to hand you a choice: 

Pay a lot for heating, or be cold. 

On the other hand, a traditional structure can be wrapped in an airtight insulating layer, and include a ventilation system. This will protect the structure and make it last longer, and will make it nice for the inhabitants, who probably do not want to live a traditional life that is not as comfortable and not as long.

In the fight for survival of traditional building, insulation, airtightness and active ventilation are not the enemy. They may be the saviour! 

References:

Pollutionwatch: wood burning worsening UK air quality, Guardian (2018, February 1st)

Steven Goodhew and Richard Griffiths (2004) Sustainable earth walls to meet the building

regulations

Emissions from Wood:

Roger Drouin (2015) Wood Pellets: Green Energy or New Source of CO2 Emissions?

The 2018 blog post hiatus

​There has been some speculation that the recent lack of blog posts is evidence that low energy building is not happening. ​I'd like to take this opportunity to state that this is simply not true.

W​e do not yet know all the reasons for this hiatus in blog posts, but low energy buildings is certainly continuing. Also there is no doubt that low energy buildings are man-made.

It would be unwise to make any predictions about the exact return and future frequency of blog posts.

In the meantime, you can make full use of the labels or search function. If you're thinking of building your own house, you may want to start here:

Ten top tips if you're thinking of building a house

Who's going to build it?

Two-by-four or zairai koho?

Part 3.14159265... How much do you need to know?

Paying for it

What exactly do you need to know about heat?

Glossary of English and Japanese terms

House of the Year in Energy Awards 2017

​Congratulations to IS Design, of Nagano City, ​winners of the Grand Prize of the House of the Year in Energy Awards 2017. Perhaps the smallest company ever to win a grand prize. More about IS in another post, but from the buildings I've seen, they deserve the prize.

​ Another ​three builders won this grand prize, followed by 63 getting a special excellence award, 137 with an excellence award, 31 special excellence industry awards and 46 excellence industry awards. This did make me wonder whether anyone was left without a prize, but also underlined the achievement of IS design in getting the top award. It also highlights how many builders in Japan are thinking about energy, and is also a reminder of just how many builders there are in this country! The list may be useful to anyone looking for a low-energy builder. Many of the builders are small, and you would need to be in their area, which is not listed explicitly.

​ An interesting feature of the list of award winners is the climate region. Japan is divided ​into 8 climate zones from 1 in the North of Hokkaido to 8 in Okinawa. In the case of small builders, this presumably shows where the building that won the award is. For national builders, presumably it shows where the award-winning building is available. Some builders will only offer some buildings in certain regions. If you are in Hokkaido, the north island, I imagine is it very easy to find a well-insulated house, and in fact it may be difficult to find one that is not well insulated. If you look at the map though, you can see the bottom tip of Hokkaido is the green region 3. And so is the north of Nagano prefecture, which is a large-landlocked prefecture rjght in the middle of the country. In fact Nagano ranges from region 3 in the snowy north to region 5 in the south and there is a marked difference between the energy standards of the buildings. Practically this means that it may be possible to get a smaller builder from the north of the prefecture to build in the south, however some of the national-scale builders may refuse to increase the spec for a building in the south because it is only in region 4 or 5. Some builders pride themselves on offering the same price for their buildings wherever in the country they are built, so their accommodation to the local climate can have implications to their bottom line.

There are more details on exact climate zones of towns and regions in Japanese here.


Below are some observations based purely on the websites of the other three winners, since I haven't had the chance to visit their buildings.

​Shimano Komuten are in ​Koyama City, Tochigi Prefecture. At the top of their website they say they are specialists in highly insulated houses (高断熱住宅). The landing page also mentions airtightness and ventilation. They give six points in building low-energy houses, the first of which is insulation. The second is airtightness, which goes into some detail about the Exel Shannon triple-glazed windows they use. Ventilation is their third point, so they clearly subscribe to the holy trinity of Passivhaus.

Their fourth point is a guarantee to keep monthly energy bills to under 300 yen per tsubo, about ​90 yen per square metre. In the first year, they will pay all the energy bills. In the second year they will cover all energy costs over 300 yen per tsubo, or if the energy bills come under 300 yen, they will give the difference as a gift. I'm not sure if I've translated that correctly, or if it completely makes sense. I guess it gives the homeowner an incentive not to overuse electricity, but it presumably also gives the builder a disincentive to make a house that will use much less than 300 yen per tsubo, but if they're actually putting up their money for the home owner's energy bills, they are obviously serious about it, and presumably have a better idea what those bills will be than most house builders. And those energy bills are pretty low. For reference, my energy bills are under 200 yen per tsubo, assuming the electricity I'm using straight from my solar panels is costing me the same as if I bought it from the grid.

Seidai​ are in Kanazawa city, Ishikawa Prefecture. ​Their building process has ten features: 1) cool in summer and warm in winter; 2) good for the health; 3) easy on the wallet; 4) long lasting; 5) very quiet; 6) strong in earthquakes; 7) flexible in planning; 8) regular consultation; 9) "after follow"; 10) environmentally friendly. ​As a deep green, it annoys me a bit that the environment is number ten on their list, but it's good to see it on the list, and it makes sense to add it after the other items that will have a more direct impact and are likely to be more urgent concerns for their customers.

The finer details include a choice of insulation materials between glass wool, sheep wool, polyester or cellulose. They also talk about airtightness and ventilation. And they too have low-e argon-filled PVC triple glazing from Exel Shannon. They also have a well-ventilated crawl space, which may be OK if it's within the thermal envelope, but I don't really subscribe to the wisdom of the crawl space when you have a modern foundation slab.

Yamato Juken​ are a large-scale builder operating in the Kanto and Kansai areas, on a different scale to the other three grand prize winners. They received the prize for the UW-Y, which is the top of their range, and also won the award in 2014.​

They are a ZEH builder. ZEH is a zero-energy policy which is slated to be a national standard by 2030. I won't go into politics here, but just note that many current politicians may be out of office by then, some of the civil servants may have retired, and slate breaks easily if it is dropped!

Yamato's policy statement talks about bringing Japanese buildings to the world standard, contrasting the average 30-year lifetime of a Japanese house with 141 years in the UK and 96 years in the US. They mention the insulation standards of Germany, and lament that while Japan produces cars and electronic goods to world standards, its buildings fall far behind.

They talk about airtightness and insulation for a healthy house. Strong houses to protect your family. Placing importance on the ideas of the customer. A commitment to health. A price you can trust that will put your mind at rest.

Looking in the details, they also have Exel Shannon's triple-glazed low-E argon filled windows. IS Design use these windows as well, which puts them in all four grand prize winners.


In their details on insulation and airtightness, I couldn't help noticing an obvious gap in the thermal envelope where they have insulated the house on the outside and the crawl space on the inside. The caption in the house says there is nowhere for the cool or warm air to escape, but can you spot it? If they can't get that right on a graphic, I worry whether they could get it right on an actual building!

Great Student Presentations

Another year and another brace of student presentations. This time, perhaps with the higher number of architecture students, there are more practical topics.

1. Energy independent buildings

One brave group out of seven decided to give their presentation in the penultimate week, and they set the bar high. One of them even gave the presentation in English, which I had suggested, but not mandated.

This began with a look at carbon emissions, and went on to talk about cogeneration, which is big in Northern Europe, but not common in Japan. The idea with cogeneration is basically to generate electricity on a small scale, and use the heat for domestic hot water and heating. They talked about a gas-operated system on the market, which seemed quite expensive as a capital cost, and also would be buying in gas and therefore no chance of being zero carbon. Of course the reality right now is that nothing is zero carbon but cogeneration has obvious energy savings.

2. Biomemetics is a really interesting topic, and the second group also did a great job.

They started by asking if we knew who had invented velcro, which we did not. The answer is at the bottom of thiw page. This is a great example of human ingenuity mimicking nature, as the inventor decided to copy some burdock seeds that had stuck to his coat and dog.

Bullet train design from the kingfisher

Another example was a bath that imitated cuckoo spit, otherwise known as the foamy spawn of the frog hopper or spittle bug. The foam radically reduces the amount of water required for a bath, and keeps it hot better!

Finally they talked about termite nests, which have elaborate vertical air circulation channels that change direction of flow between night and day, keeping the building cool or warm. They are also porous to allow carbon dioxide out. This natural design was imitated by the Eastgate Centre in Harare, Zimbabwe, which was designed to cool by entirely natural means.

3. The next group talked about Energy Standards in Five Different Countries.

These were the US, the UK, Germany, Korea and Japan. The introduction explained what was specified in the building standards, and went on to show how relatively lax Japan's standards were and what a low proportion of PVC windows Japan had, but also showed that Japan has
the lowest energy consumption per household.

A comparison was made between Japanese buildings and South Korean buildings, where respectively rooms are individually or collectively designed. It was argued that Japanese design allows rooms to be heated individually while Korean design, and that of Europe and the US, typically requires that the whole building is heated.

To be honest, I was not completely convinced by this, and look at it rather as holistic design allowing whole buildings to be heated, while the Japanese vernacular discourages it.

They concluded that there were many different approaches to low energy standards, that the Europeans are working hardest to lower environmental impact, and that Japan is behind other countries, but that there are plans for Japan to have low energy standards by 2020.

A questioner asked why Japan—ostensibly a developed country—has such weak building energy standards. A couple of answers were given, one by one a presenter, and one by the questioner, which was supported by another of the presenters. A discussion of this needs a whole other blog post, and in fact I've already written one here!

4. The Latest Low Energy Buildings was the topic of the next group.

The first speaker talked about the Cardboard Cathedral in New Zealand, built after the 2011 Christchurch earthquakes. Another was built in eight months in Kobe Japan, intended to last two or three years, but still in use ten years later. A good example of low embodied energy.

The second speaker talked about Ichijo Komuten's i-series of low-energy buildings, which are the closest thing to Passivhaus at scale in Japan.

The third speaker talked about ZEB—Net Zero Energy Buildings—giving an example of a building using a combination of solar power and biomass to meet all its energy needs.

The fourth speaker talked about the Zollverein School of Management and Design in Essen, Germany which the presenter rather suspiciously described as choosing geothermal energy rather than insulation. It got away with a thin concrete shell with naturally occurring hot water
piped through.

I couldn't help feeling that maybe the pipework and certainly it's maintenance would be more expensive than insulation.

Also I notice that they are only talking about Japanese buildings, and buildings by Japanese architects, which is a curious position in light of the last group's findings on Japan's low-energy building credentials.

5. The next topic was Hydroelectricity, which is probably the cheapest and least fossil-energy demanding source of electrical power.

They discussed pros and cons, different systems of generation and then some interesting ideas on microgeneration from domestic water, one taking energy out of the incoming pressurised water main, the other out of water coming out of taps. I didn't want to ask them about any conflict with the need to save water in the house, and whether the mere hundreds of milli-watts they could get from the taps was worth it, but the idea of looking for energy sources is a good one.

Habitat 67—because modern architecture means ignoring physics

6. Famous Buildings was the topic of the next group.

The Farnsworth House in one of the four seasons it is not fit for

I worried this would just be a slide show of beautiful buildings, and have nothing to do with the subject of the course, but this group set their parameters well. They were looking at a few famous buildings from the perspective of form factor, thermal bridges, materials and windows, pointing out both good and bad points. Though mostly bad!

Their buildings were by Hundertwasser in Vienna, Habitat 67 in Montreal, Canada, the Farnsworth House in Illinois, USA, and the Gassho-zukuri houses of Shirokawa village in Gifu, Japan.

They did a nice assassination of the form factor of Abita 67, and showed how Farnsworth's concrete sandwich with glass is more of a sacrificial altar to comfort and energy use than a useful contribution to architecture.

7. The final presentation talked about the Merits and Demerits of Low Energy Buildings.
They did as good a job of concluding the course as I could. The demerits included the extra costs and the lack of skilled designers and builders, and the presenter hoped that everyone in the class would be working to change this.

Answer:
Velcro was invented by Swiss electrical engineer George de Mestral in 1948. For any etymologists out there, the word is a portmanteau of "velvet" and "crochet".

Building Jokes

There was a tweet a while a ago from Nick Grant @ecominimalnick with a picture of a structural engineering joke.

I didn't get it at first, but the joke is that the round black things with the bolts in are supposed to be stopping the walls from bulging, by bolting them onto the floor. Clearly the floor is not in the middle of the windows. This may be a deliberate joke, but I don't think the other pictures are.

A couple of my students did start laughing when I showed them this picture, which Sam sent me. I'd been talking about the relative merits of glass, air and aluminium in window construction, and they found this very funny, although I doubt the joke is deliberate.

I asked them to calculate how much glass and how much frame there was. They all guessed around 70% glass and 30% frame, but actually it's closer to 55% frame and 45% glass.

It's even funnier when you notice the unmelted snow, and see where the sun is coming from and realise this is a North-facing window. So not only is the aluminium going to reduce the performance of the glass, it's not going to get much sunlight coming in. It's possible there is some fantastic view that these windows look at, but even then, most of the view will be obscured by frame.

Of course traditional houses in the UK aren't much better.

I also showed them the windows below from a brand new concert hall in a nearby city. Due to my photographic inability, it's a bit difficult to work out what's going on, but basically the external surface area has been needlessly increased by around 20%, and it's aluminium too.

This time the joke is on the city tax payers, who will be getting the heating bill.

How to build a house part 5: What exactly do you need to know about heat

Some people spend six years studying for architecture degrees, and it can take a lifetime to build the perfect house. In fact it's now 90 years after Gaudi was knocked over by a tram, and his is still not finished. Admittedly that wasn't your everyday family house, but I digress.

So, you'd like to build a house in the next year, and you're also going to be busy at work, and spending time looking after your family. What do you really need to know?

If you're trying to build a low energy house, two important areas of knowledge are thermodynamics
and economics. Structural knowledge is essential, but if you are working with professional builders in Japan, they should have all the structural knowledge necessary to keep your building standing, probably even through the strongest earthquake ever.

As well as knowledge of what to do, you need to know how to do it, and procedural knowledge is also important. So you need to know how the design process works, but I'll get to that later. First, here are five things you should know about thermodynamics. In most places in the world, the biggest energy use of buildings is heating and cooling.

1. Heat will leave the building by the easiest route in the winter. And it will get in by the easiest route in summer. Heat is a lazy opportunist. This means that you should be worrying about the parts of your walls, ceilings and floors with the least insulation rather than being impressed by the parts with the most insulation. Be aware of the performance of doors and windows, and anything in your thermal envelope that is poorly insulated. There may be conflicts between the structural desires of the builder and the thermodynamic needs, but it is possible to make buildings that are structural sound and thermally right.

2. There is less heat loss as walls get thicker and areas get larger, and more heat loss as temperature
differences increase. So thicker is better for your walls and roof, and smaller is better for the surface area of your house. When you are designing the house, you can't do anything about the temperature. It will get hot and cold outside, and the people inside will want the temperature to be within their comfort zone. If the building does not deliver that comfort zone, the people in the building will use electricity or other fuel to change the temperature.

3. Heat loss depends on the insulation performance of the material in your wall, roof, floors and foundation. Very broadly, metals are the worst insulators, or the best conductors, followed by earthy things, including stone, concrete and glass. Next come plastics, which we can start to call insulators, then fibres, which include wood. Foams are generally better insulators than fibres. In both cases their
performance comes from the excellent insulation credentials of air, but foams also stop the air from moving, and in some cases can use different gases to air. Other gases are better insulators than air.

This table shows the thicknesses of different materials needed to get the same insulation effect as 10 cm (4 inches) of glass wool. Depending on where you are in Japan, you may need the equivalent of 20 or 30 cm of glass wool to make a low-energy building.

-->

Krypton (gas)	2 cm	three times better than air
Argon (gas)	4 cm
Phenolic foam	5 cm	twice as good as glass wool
Air	6 cm
Polystyrene, expanded styrofoam	8 cm
Glass, wool Insulation	10 cm	three times better than wood
Cork, re-granulated	11 cm
Hardboard high density	38 cm
Wood, oak	43 cm	three times better than medium concrete
Polycarbonate	48 cm
Concrete, lightweight	50 cm
Polyethylene low density, PEL	83 cm
Concrete, medium	1.4 metres	thirty times better than stainless steel
Concrete, dense	3.5 metres
Stainless Steel	40 metres	twelve times better than aluminium
Brass	270 metres
Aluminum	500 metres	Yes, half a kilometre!

4. There are five to ten litres of moisture in the air inside your house, and given any opportunity it will build up and cause condensation, mold or rot. This happens where air is not moving and there is a cold spot or a sharp temperature difference. It will happen where you are not looking, possibly on your favourite coat. This can be stopped with airtight insulation.

5. Reflective coatings are a good idea, since they will reduce the amount of heat radiated in or out of your house. However, most heat is lost through convection or conduction, so the first priority is to add insulation. Things that look shiny may just look shiny.

Bonus: It may be useful to know how a heat pump works. There's a great explanation here using a rubber band refrigerator.

Note

While 500 metres of aluminum has the same insulating performance as 10 cm of fibreglass, metals are not effective as insulators. As the insulation gets thicker, the outside area of the house also gets bigger, so you will more heat, not less heat, as you put on more layers.

How to build a house in Japan part 3.14159265... How much do you need to know?

Disclaimer: you're going to have to wait for the next post if you want some ideas about exactly what you need to know.

If you buy a car, you don't usually start making suggestions about where to put the seats, where the filler for the fuel tank should go, or the timing of the spark plugs. But when you build a house it's possible to make all kinds of request and suggestions. You may also have noticed that almost all cars are built in factories, where standard parts are assembled in quality-assured processes. Although cars were all bespoke in the beginning, to build a car by hand now you would need a lot of expertise, time, money, or perhaps all three.

It's tempting to think that the same economic forces will push all houses to be factory-built, leading to higher quality and lower cost. But that happened to the automobile industry well within a hundred years, while house building is perhaps a hundred times older, and many houses are still built by hand. So some other factors are at play. Of course there are logistical issues with actually building houses in factories: wall and roof structures can be factory-produced and assembled on site, and sometimes are, but it would be very difficult to transport whole buildings over inevitably large distances from these huge factories. Cars, on the other hand, could be literally driven off assembly lines.

Another conclusion is that building a house is much easier than building a car, and it is within the capability of many more people. So one question you may want to ask is: how much do you need to know to build a house yourself? The short answer is that if you can ask that question, you probably know enough, or at least will find out enough in the process, which you should appreciate will take at least a couple of years.

But before you start thinking about doing everything yourself, how much do you need to know before you start commissioning others, and looking at part 4, which is paying for the project.

High-volume, low-cost builders are likely to give fewer options, but as the scale comes down and the price goes up, so do the choices you can make. Building professionals should probably be giving clients simple choices between limited options or within small ranges, with the kind of user friendliness that Steve Jobs brought to Macintosh. But people do have opinions about the way a house should be, and it may not be on the menu. These ideas may be based on things you have in your existing house, things you saw in someone else's house, things you read about somewhere, or something from your fertile imagination. Whatever ideas you have, if you are paying for your own house, it's reasonable to request it to be your ideal house.

Really?

But be careful of what you wish for, as you might just get it. Indeed your imagination may be playing around with what some of those things in other people's houses and in magazines actually are or do. And if you have a great idea for your house, but have never seen another house that uses that idea, then it's possible it's not actually a great idea, and there are very good reasons for not doing it. It's also possible that you have just invented something. 

And it's also possible that it is a great idea and has been used in several other houses, but you just haven't seen them. If the architect or builders tell you it's impossible it may just be beyond their experience. I remember in the early stages of our project suggesting to the architect that we could take heat out of the air leaving the house and use that for generating hot water. The architect laughed at me. Later I was talking about the same thing to the passive house lady, and she said, "Oh yeah, that's what they do in Sweden."

So visit as many houses as possible. You can also look at houses in magazines, but beware that they may be idealised houses that are lived in very differently, and any of the features may have lost their sparkle a couple of years, or even a couple of weeks after the paint dried. Or the features may still be there but are invisible under layers of magazines, homework the kids didn't do, bits of clothing that you're not sure who left behind, and jars filled with pens that mostly don't work.

The internet is a great source of information and you may often be in a position where you know more about a topic than the professionals. Materials and techniques around the world are developing all the time, and what your architect learnt at college twenty years ago may have changed, been superseded or debunked. Watch this you tube video for some brilliant tips for doing it yourself. I particularly liked the idea of putting a rubber band over the head of a worn-out screw to get some purchase on it. But also remember that a lot of professional builders now make a living from correcting projects by people who watched one youtube video and thought they knew what to do.

Stick some foam in, she'll be right! (not)

But beware of the Dunning-Kruger effect. This means that your ability to know how good you are at something depends on how good you are at doing it, because the skills needed to judge an ability are similar to the skills needed to have that ability. This should make you humble about your ability to specify the building you want, choose contractors, or take on a project management role. It may also apply to the architect or builder if you are expecting them to do something new. They may have no relevant experience with insulation, airtightness, installing high performance windows, ventilation systems or any other features essential to low energy buildings.

So when talking to professionals, while they probably know more than you know, remember:

• they probably know less than they think they know 
• you probably know more than they think you know
• you may know less than you think you know

People say that a little knowledge is a dangerous thing, but in fact any amount of knowledge can be dangerous.

Note: 

1. For most calculations, pi is a bit over three. The precision in the title would give you the length of a piece of string around the equator to within 40 centimetres, if the earth was perfectly round, which it is not, and you knew the diameter to within a few centimetres.

2. How long is a piece of string?

Top Ten Top Tens

I've already posted my own top ten tips for building a passivhouse and posted about Alessandro
Merigo's but I've now added eight more to give you a top ten of top tens. Please note that most of these will just appear on one internet page, and none of these are click-bait with a button for the next page hidden between several traps.

1. Here are my ten tips for building a house.​

2. Alesandro Merigo's ideas are here:

3. Dieter Ram has ten principles for good design, which apply when designing anything.

4. Interestingengineering.com has an engineering perspective, which is close to my own ideas in
Ten Amazing Tips for Building Energy Efficient Homes.​

5. Think architect has Design-based ideas for building affordably.

6. Finder.com.au have the top 10 most helpful tips for building a house.​

7. NZI Architects expose 10 myths about architects.

8. Freshome.com has ten mistakes to avoid when building a new home, although I'm not sure about their advice to have as many windows as possible, and to think about skylights. I'm beginning to wonder whether I should have stuck at seven.

9.  LotNetwork.com has Ten green home building ideas, although they don't talk about the importance of insulation. Green may be more of a colour than a practical strategy to save the planet.​

10. And just in case​ you now need them​, here are ten tips on anger management from Mayo Clinic.

How to build a house in Japan Part two: Two-by or zairai?

One choice that you probably won't be given by any architect or builder in Japan is whether to build in zairai koho or two-by-four. If you're building a wooden house it's a choice that is made early in the project.

Zairai koho is the traditional wooden building technique in Japan. It consists of a framework of pillars and beams,​ fit together with joints carefully designed to avoid excess stresses, and​ originally held together without any nails or screws, hence the nickname nail-less construction. The standard section size of the pillars is 120 by 120 millimetres, and the beams are multiples of this.

Two-by-four refers to a building technique using beams of two-by-four inches. Rigid panels such as plywood or OSB are added so the structural strength is based on the walls, where zairai traditionally relies on the pillars and beams for the structure. Just to add a little confusion, 2 x 4 beams measure half an inch less by the time they've been cut and dried, measuring 38 x 89 mm rather than around 50 x 100 mm that you might expect.

The two-by-four construction technique developed from balloon framing in the 1830s in the US. It allowed standard sizes of timber to be put together with mass-produced nails by relatively unskilled wood workers.

Compared to zairai, two-by-four constructions is probably cheaper, stronger, easier to build, and easier to insulate. Since the beams are rectangular rather square in ​section, the building more efficiently derives structural strength from the wood. Insulation can be added between pillars and studs, and the wood make​s​ up a smaller proportion of wall, so the insulation performance will be better than a building with square pillars. If the same technique uses 2 by 6, 2 by 8, 2 by 10 or​ even​ 2 by 12 beams, a suitable thickness of insulation can​ easily​ be added between the beams.

It's difficult to find tangible advantages to zairai construction, but I will try.

Zairai construction is traditional.

That ​is probably enough to illicit approving nods from fans of tradition, and disparaging scowls from anyone who has been paying attention since the Age of Reason.

Zairai construction is based around standard sizes and scales that suit the human body. Measurements are in the traditional units of shaku and sun. One shaku is within a hair of an imperial foot, and was standardised in 1891 to 10/33 of a metre. Traditional Japanese units are decimal, so a sun is one tenth of a shaku. Traditional zairai beams are 6 shaku, or 180 cm, from the floor. That's around my height, and​ after a few years living ​in a traditional Japanese house I was beginning to develop calluses on my forehead and a stoop in my back. The average height in Japan increased 8 cm in the second half of the twentieth century, so I suspect for most of the history of Japanese architecture, the lintels were at an appropriate height. ​In modern houses they are higher. Of course there is nothing to stop you from using human-scaled dimensions in a two-by-four construction. Also, you may have noticed that the shaku is remarkably close to the imperial foot, and the standard lengths of two-by-four (inch) beams are all in feet.

Zairai construction is based on a woodworking tradition at least a thousand years old, which can be seen in the oldest and the largest wooden structures in the world. By building a house in zairai you are helping to keep this tradition alive. But what exactly is being preserved? Why do home builders have to pay more to preserve it? They still make temples and shrines, so couldn't the fantastically wealthy priests preserve their tradition?

The joints of zairai are all supposed to fit together without any nails, except now they do use nails.

bolts​ or other connectors for the joints. And since the traditional pillar-and-beam structures do not meet modern earthquake regulations, to get planning approval for zairai buildings, you need to add structural walls, just like they do in two-by-four construction.

The square beams were traditionally prepared locally from​ round​ trees. Now timber is usually cut in saw mills, often using state-of-the art CNC machinery.

​So is your modern zairai building just a two-by-four construction with more wood in it, and more complicated joints?

I guess you could see an advantage in it being more difficult to build, since that means you have more highly-skilled carpenters. You have to squint a bit to see this, since you are also making the job more difficult, but there are some places where more highly skilled wood workers will make a tangible difference to your house.

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Our house uses zairai koho, and it is on the list of things I would probably have done differently. Luckily ​that​'s a short list! The point when I realised that there had been a different option to this vast array of square-section wooden pillars was at the stage in the process where it was not possible to change the building technique.

You're always at some ​stage in a process.

There had earlier seemed to be a great rush to get the structure all sorted out, coinciding with a busy time in my day job. I was a bit disappointed as I was quite interested in structures, and would have liked to have had some input into it. It seemed like a lower priority than the insulation work and the systems we were considering, so that was a battle I chose not to fight. Qualified architects in Japan, or anywhere else, can be trusted to make structures that will not fall down.

After this urgent decision had been made​ to finalise the structure​, there seemed to be a couple of months when absolutely nothing happened. Ben talks about a similar artificial deadline in his retire Japan Blog and I think this is a common technique in the building trade.

When we were looking at ways to fit at least 250 mm of insulation into walls with 120 mm pillars, I had an idea of using two-by-tens as studs between the ​load-bearing ​pillars, which would have allowed one insulation layer rather than the three we have ended up with. This seemed like a bad idea as it was mixing two different techniques, and would leave a few awkward sized gaps. So I wondered about getting rid of the square pillars ​altogether ​and just using two by tens throughout.

As you will remember from lesson 4, the calculation of the thermal performance depends on how much wood there is in the insulation layer. This information needs to be added into the Passive House software, and I was checking the figure of 18.1% that we had. A more conservative estimation put it more like 25%, so a whole quarter of the wall was made up of wood, much of it by square pillars. This could have been halved by switching to rectangular sections. That would also have meant less wood​ to pay ​for​.

I suggested this to the architect who said it would take a month or two to change the structure, and he'd need to get someone else to calculate the stresses.

So we have a house beautifully built in wood, but ​we can't see any of it it, since it had to be covered to meet fire regulations.

How to build a house Part Zero: A world of pain!

A lot of people have an idea about an ideal home.​ Some have dreamed of it for years, some have an evolving plan in their heads. ​But unless you are very humble or very rich, the ideal home will be beyond your budget​, and ​unless you are very practical​ or somewhat unimaginative it will ​probably ​not be physically possible to build.

​On top of this, people tend to embark upon building projects with partners, spouses or other family members​, and the chances of two people sharing the same aesthetics are small. ​The process of building a house involves a steady erosion, and sometimes brutal ​dismantling of your dreams.​ The paradox of the creative process is just how much destruction is involved. Rather than lofty ideals, the battle is ​usually ​won by our incredibly low standards ​for acceptable living conditions​, and our ability ​to adapt to our environment. We are often like lobsters in pans of steadily warming water, who will never try to jump out even as the water boils.

Des res in Ishigaki.

We have ​a stereotype of the cavemen, living in dark, damp caves. I'm sure some of them did, but for the most part that is probably just where they died, especially if they did something as stupid as build a fire in an enclosed space. The only reason we have such ancient archaeological remains from caves is because the caves preserved them so well.

They said they'd be putting the roof on next Tuesday.

​Evidence of other structures goes back​ to​ remains​ found in Japan half a million years ago. A couple of years ago we visited the Saxon village at West Stow in East Anglia where they found some remains of structures a mere one and half thousand years old. At first they thought these were pit-houses, and they tried to reconstruct these dwellings with a roof over the pit in an enterprise called experimental archaeology. After trying to live there, the experimental archaeologists soon found how unlikely they were to have been pit houses, since the pits rapidly filled with mud and water. Instead they hypothesised floors were built over the pits. So old buildings were probably less primitive than we think. At the same time, it's hard to believe that shoddy building is a new phenomenon. Here's a story ​from the BBC ​of someone who found hundreds of things wrong with his new house, in case anyone thought building in the twenty-first century was perfect.

Brand new sling.

We also visited Greece, and saw throughout the countryside partially finished houses which people had begun to live in but left floors or walls missing for tax reasons. As I visited ​some of the ancient remains I begun to wonder whether they were really in a state of decay or whether they had just been half-built in antiquity. 

Same old rock.

So back in the new house project, at some point Stockholm syndrome sets in. Stockholm syndrome was named after a bank raid in the Swedish city when bank employees were held hostage over five days in 1973. The hostages developed emotional bonds and loyalty to their captors over this time. It took less than a week. Five days was enough to not only develop love of an aggressor, but also coin a term that we still use half a century later. And this is about the time it takes for you to become a hostage of your house. You may develop the syndrome with your architect much earlier.

And then when it's finished, you'll end up being sent something like this satisfaction questionnaire.

Read about Ben's housebuilding adventures here on Retire Japan.

A plastic bottle house and other stories

​I've always had a problem throwing things away. A lot of people see an empty bottle and think it needs throwing in the bin. I think what a fantastic piece of engineering it is, how many possible uses it could have, and how long its life could be. So I found this article from the Guardian about buildings made of plastic bottles particularly interesting.

​In other news, here's an examination from the Zeitgeist Is Changing blog debunking the "wind farms kill birds" meme. It puts fossil fuel power stations fifteen times more dangerous to birds than wind farms. 

And this article from the Guardian about a Green-powered boat preparing for a round-the-world voyage has been sitting in my drafts folder since September.

This is supposed to be following on the coat tails of Solar Impulse, which set several aviation records and was a genuine testament to the state of renewable energy and a gauntlet thrown down for bigger and better air craft to follow.

But this green boat is not going to come anywhere close. For a start any claim to be the first zero-carbon circumnavigation of the globe ignores at least five hundred years of wind-powered journeys starting with Magellan. And even then, most of the places he travelled were already inhabited, and the natives had not arrived there by jumbo jet.

There is a claim that this will be the first round the world trip using renewable energy and hydrogen fuel. And it will probably be the last. Hydrogen is a ridiculous way to store renewable energy. As we have seen in EROI, solar power is just becoming a viable source of power in terms of the energy it will generate over the lifetime of an installation compared with the amount of energy needed to install it. Electrolysis is a great way to produce hydrogen... in your bedroom. As a commercial process, it is very energy intensive.

The comments below newspaper articles are usually full of profanity, insanity, and complaints but these comments contained a lot more insight than the article itself.

How to build a house in Japan Part One: Who is going to build it?

If you want to have a house built in Japan, you have three basic choices: a large-scale "house maker" 大手ハウスメーカー, a local builder ("komuten" 工務店), or an architect ("kenchiku sekkei jimusho" 建築設計事務所). It's unlikely that any of these people will tell you about the other options since they have their own commercial interests in the way they do things.

Around a third of new homes in Japan are built by large-scale builders. They​ are​ usually​ relatively expensive, you have a limited range of designs to choose from, and variation may be impossible or charged extra for. What you get will look very similar to the catalogue or the model house, and the support will be good. Actual energy use will often be a lot higher than predicted, but that applies to most non-Passivhaus buildings. If you can find a house maker you like, building through them will be the smoothest path to your own home. Some of the house makers are working hard on low energy buildings, and Ichijo are getting close to the Passive House standard. ​Most are governed by market considerations and long-term relationships with suppliers, so standards are often minimal. ​In theory large​-​scale builders can use factory assemblies to produce high quality at low cost​, so in some cases these houses may be cheaper, and if the economies of scale really do work, that's the way house building may ultimately go​.​ We buy cars off production lines, so why not houses?

An architect should be able to build anything you ask for, or at least will be​​ able to draw it. There is a risk that you may not get what you want, either through miscommunication, practical issues or the fact that architects have their own agendas ​and aesthetics, ​and your house is one​ small piece of that jigsaw puzzle. Perhaps worse, you may get exactly what you want, but find when you move in that you didn't want that after all! Building through an architect will often cost less than a house maker, but there is no guarantee. This ​route ​will work best if you find an architect who shares your idea of an ideal home. If you​ can​ find an architect ​​interested in ​building a ​​low-energy house, with some experience in highly-insulated highly-airtight buildings, then it should come out cheaper​ and higher quality​ than the house makers. If you treat the architect as if you were commissioning a famous artist to create an artwork, then this will go smoothly. Smother still if you imagine the artwork will be displayed in a gallery that you can visit if you want to. Of course, back in the real world it's going to be a house that you'll be looking at it every day, and usually concerned about its function rather than its form.

Going straight to a komuten will give you more freedom than a house maker, but not as much as an architect, and they will probably be cheaper than either. A komuten will ​often employ ​at least one ​qualified architect who ha​s​ all the technical skills and legal qualifications to build a house. Ninety percent of the building companies in Japan produce fewer than ten houses a year, so there is a very long tail in the construction industry. Finding the right one for you, in the right place, may be more tricky.

There is a grey area between ​a​rchitects and ​k​omuten, in terms of finances and project management. Architects do not build houses, and ​the construction of ​your house will probably be​ carried out by a komuten whether you choose an architect or a komuten. In fact even some of the large​-​scale builders contract work out to komuten, so it's possible that exactly the same people ​will be building your house whichever route you chose.

The basic role of architects is to design the building, and in the simplest case they will do that​ only, and hand over the plans to a builder. ​More often the architect will see the whole project through, and may act as the project manager. When it comes to payment, ​the architect may charge you for the whole lot, and subcontract the komuten and other contractors. Or you may pay the komuten and the architect works for them. In either of these cases there is one person to negotiate prices with, and as a customer it is clear who is responsible if something goes wrong​.​ ​W​hich it probably will since houses are complex, and building is more art than science. Alternatively, the architect may charge a fee and you pay the komuten separately, but the architect will stay on to oversee the project. This may be less ideal.

The carpenter is really important if you're building a wooden house, and in fact carpenters used to build houses in Japan without architects, ​and they are part of a long tradition. This may not always be a good thing ​if you want to build a ​low energy house​ since​ you sometimes need to go against building tradition. ​Many of the older people in the building trade have basically decided on the way things should be done, and it may be very difficult for them to try new approaches. In fact they may see new ideas as direct threats to their livelihood and will be hostile towards them. Younger people may be much more open to ​new ideas, but of course they have less experience!

​Another potential danger ​is choosing a friend to build your house. ​You may feel a great sense of security relying on someone you know well since building a house is a daunting process. However, there is always a danger working with friends, and w​ith as big an investment as a house​,​ the danger is potentially very big. If things go wrong, then you may lose your friend​.​ Even if things go well, ​you may feel that you are helping them as a customer by giving them work, and they may feel they are helping you by working for you, which could strain the relationship. ​If it is a very good friend, then your friendship may be too much to risk for something as trivial as a house, and if they are not a very good friend, you have no reason to choose them above anybody else. You should be choosing the people who are going to build the best house for you. Of course things may go smoothly, and ​it may turn out that your friend is the best person to build your house, but that should be the end point, not the starting point.

​Note: ​In Japanese, Ichijo somewhat confusingly calls itself Ichijo Komuten, but they would not be described as a komuten​.​ ​I​n fact​ they​ have operations in the US and Australia as well as in Japan.