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?

How to Solve Problems

Teaching is a constant learning process. At least it should be. One problem with being a teacher is that you often get into situations where you think you're right, which can make it difficult for you to change what you're doing. In the classical model of the teacher, you can be expected to be right in your knowledge, otherwise you wouldn't be there. But when it comes to how to share that knowledge, or in what order to present it, there is less clear right and wrong and just a whole range of choices.

I believe in the power of problem solving for teaching. This translates to a belief in the power of learners to solve problems, and for them to learn something in the process. The problem is, not all learners are good at solving problems, and many have been through educational systems where they have not been expected to solve them. At least not the kind of problems that I give them. 

So how do I solve this problem?

Given that I want to teach problem solving skills, I probably just have to be a lot more open and transparent about it. I have been mentioning a few things to the students in passing: like suggesting they draw diagrams to help them work out problems, or advising them to write their calculations out carefully and clearly on lots of paper so it's easy to go back later and see what they did. I need to be much more explicit about the steps of the problem solving process, and give them a bit more practice in each step rather than just throwing a problem at them and hoping they'll work it all out. Too often the problem I've been throwing at them is how to solve problems, which is way too abstract.

Here are some steps:

• Formulate the problem

The first step is to work out exactly what the problem is. Draw a picture. Write down what you know. Draw another picture. Put question marks where you need to find an answer. 

• Find solutions

Now that you know the problem, you can think about solutions. What strategies are available? Are there different ways to solve the problem. Make a list!

• Choose a solution

Which is the best way to solve the problem? What are the steps? 

• Prepare tools

If you are calculating, your main tools are equations. If you are using a computer, the tool is the software. You also needs data. There will be physical properties that need to be looked up from tables, some things may need to be measured. Some will need to be estimated.

• Calculate

Use lots of paper. Avoid any shortcuts that will not be obvious to someone looking at the calculations later. If you miss out steps on paper, there's a higher chance you'll make a mistake.

• Check the calculation

Ideally get someone else to check your calculation. It's often difficult to see your own mistakes.

• Check the answer

Eyeball it. Compare it with your real world experience. So you calculated that this pencil weighs a million tonnes? Maybe you should think again.

• Check the error

Answers in the real world are never perfect. Their accuracy depends on the accuracy of the numbers going in, and the accuracy of any equations you used. Know how wrong you are!

That's eight steps, and no fancy acronym to go with them. I can start building them into my lessons and watch what happens.

It's probably also worth talking about engineering problems and how they are different to the problems that come up in education. They have often been conditioned to find one correct answer, but over in the real world there is usually more than one answer, and more than one way of finding the answer. Good engineering will find the best solution to a problem, given a range of criteria. The most important considerations are often cost, safety and performance, and the best solution may be optimised between them. Cost itself can be in materials, equipment and construction processes. 

Of course one factor in this optimisation is the length of time the engineer spends on the problem itself, since engineers are a scarce resource and their time precious.

So I think I've written enough on this topic for now.

[Image taken from https://schooltutoring.com. not sure where they got it from!]

Low Energy Building First Class Fact Checking

The first lesson has some background on the energy problem. I have the carbon graph, showing the emissions taking off around 1800, driven by a smooth exponential growth in coal production. Actually the coal was not really being produced—that happened back in the carboniferous period 300 million years ago—it was being moved around and then burnt. The graph shows oil starting, then gas a little later, each in its own exponential variant. Meanwhile, the emissions from coal have still been increasing. 

I've been saying "until this year" with a quizzical optimism, and finally it looks like "production" of coal is down, which is a sign that we will eventually burn less of it. 

This graph from BP is still pretty scary.  That gray coal line definitely seems to be getting thicker. Also alarming is the sandy bit at the bottom, which is biomass. Before coal that was the only source of heat, and it was more or less constant until the middle of the twentieth century. Now that is on the rise. I'm not sure how much is in industrial use of biomass, for example replacing coal in thermal power stations, and how much is domestic use from fuel-poor burning what they can find. 

If you look carefully you can see the thin yellow strip of renewables at the top, like a sprinkling of snow on a mountain top. While this has increased from its previous levels of invisible and insignificant, it is still a long way off replacing any of the behemoths beneath it.

It should be noted that while BP's data can probably be trusted, their main business is still in selling fossil fuels, and their business model is still based on selling more. The graph goes up to 2013. 

The next graph is from the International Energy Agency, and gives us hope that 2013 was around the high point of coal, with production in China and the OECD decreasing. It's tempting to see that as a peak, and look forward to a steady then rapid decline in coal extraction.

However, Dick Van Dyke nostalgia has been strong in the US, and production was up last year. So, once again, it's too early to tell.

I guess it depends on who wins between the people selling fossil fuels, and people promoting energy efficiency and renewable energy. 

While checking figures, I also revised the proportion of Japanese energy that is imported from 80% up to 90%. The lower figure was pre-Fukushima, which had got into my slides at the beginning, and I've now corrected several years late. (Japan was 20.2% energy self-sufficient in 2010, and 8.3% self sufficiency in 2016 according to METI.)

I had been telling student that Japanese houses use 30% of the country's total energy, while in fact its more accurate to say that buildings in Japan use around 30% of the total energy. 

Whichever way you look at it, the amount of energy imported can be reduced if we get serious about low energy buildings.

I also found some interesting changes in energy use, which I may need to mention some time, although should probably work out more carefully first. 

Between 1973 and 2015, residential energy use in Japan increased by 90%, office energy use increase by 140% and industrial energy reduced by 20%. 

I'm not sure to what extent this is a sign that houses and offices have become much less efficient, while industry has become more efficient, or whether it shows that Japanese industry is producing less, and people are spending more time in offices and more money on energy-consuming appliances in their houses. 

(Dick Van Dyke from trailer screenshot - Mary Poppins Trailer, Public Domain, https://commons.wikimedia.org/w/index.php?curid=34700974)

Low Energy Building Course: Every Tuesday Afternoon—Starts 2nd October

Not only can students at my university take the 15-week Low Energy Building course, it's also open to members of the public!

You can read the syllabus below. And find more information about other courses open to the public here.

See you in room 26 half past two!

(1)授業のねらい	【授業の達成目標】 ・Students will learn how basic science affects buildings ・Students will learn how buildings affect the environment and how culture affects building practices 【授業のねらい】 Buildings use over one third of all energy consumed in Japan, as in many other developed countries. In a world of increasing population and limited fossil fuel reserves, reduction in building energy consumption is important. As well as drastically reducing consumption, low energy buildings can be more comfortable, more healthy and less expensive over their lifetime. This course will introduce students to the principles, the practicalities, and the future of low-energy building. 他の先進国と同様、日本で消費されているエネルギーの3割は、住宅で使われています。人口が増加し、化石燃料が限られてくる世界では、省エネルギー住宅が必要となります。エネルギー消費を減らすことで、居住者に快適で健康的な暮らしをもたらし、建物の耐用年数においても経済的です。本講義では、省エネ住宅の仕組み、その実用性と将来について紹介します。
(2)授業の概要	This course will show how simple scientific principles affect buildings, and how insulation, airtightness and good windows can lead to houses with very low energy consumption. We will see how the use of solar power can make buildings that produce energy. We will look at low-energy buildings around the world, including the German Passivhaus standard. We will also consider the design process, including compromise, optimisation and guesstimates.
(3)授業のキーワード	環境、物理学、建築、省エネ、熱力学、太陽光発電
(4)授業計画	1. What is a low-energy building? 2. What is energy? 3. Insulation and thermal envelopes 4. Compound insulation and thermal bridges 5. Why do we feel hot or cold? 6. Air and water 7. Windows 8. Ventilation 9. Windows 2.0 10. Energy standards and low-energy building around the world 11. To zero energy and beyond: Buildings as solar generators 12. Passivhaus 13. Economics and ecology, embodied carbon and life cycle analysis 14. Presentations 15. Review This plan may change to meet the needs of the class
(5)成績評価の方法	Students must complete weekly online activities in eALPs to pass this course. Students will be expected to participate in class and give presentations. Online quizzes: 80% Online forums:  10% Presentations: 10%
(6)成績評価の基準	The university policy states that students need 60% to pass, 70% for a B, 80% for an A, and 90% for an S.
(7)事前事後学習の内容	Additional information will be made available on eALPS.
(8)履修上の注意	The class will mainly be conducted in English. It will be possible for students to ask questions, complete assignments and give presentations in Japanese. 本講座は主に英語で行いますが、受講生からの質問、課題の提出、発表は日本語でも結構です。

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!

Slightly unhinged

With the parts in hand, I was worried there could be another few months waiting for them to be installed. Yamazakiya were too busy, and they sent another window installer, all the way from Tokyo, to put our new hinges in. They came 24th February.

The hinges are pretty simple. Basically two hoops stuck to the wall, one hoop between them stuck to the door and a pin down the middle.

Just in case anyone is thinking of coming round to my house and breaking in by removing the pins and taking the door off, I should tell you that there are allen screws holding the pins in, that can only be accessed when the door is open. Also, even if you did get the pins off, there are plates and grips on the hinge side of the door so it will only open by swinging. So when it's locked, it's locked. The door designers are one step ahead of burglars, although I sometimes think the people who made our windows have similar moral solvency.

Although simple, the geometry of the door means that the axis of the hinges must be in the same place, so we couldn't just replace the hinges with any others: we had to get the same hinges.

To replace the broken hinge, they needed to
1. take all three pins out,
2. remove the door,
3. remove the screw from the broken part of the hinge,
4. replace it with a new unbroken part,
5. put the door back in again,
6. put the pins back in.

Sounds simple, but the door weighs over 100 kg.

I was expecting them to have some fancy door installing equipment that would be able to hold the door in the right orientation and steadily move it away from the opening. They put a blanket underneath the door, and one of them rather quickly took the bottom pin out while the other was holding on to the door. I wrote above that the first step was to take all three pins out, but in fact the top hinge was free from the door, so only two pins needed removing.

I suggested they should put something a bit more substantial under the door to keep it at the right height. They first asked if I had a piece of wood, but then I held on to the door while they fetched some from their van.

I began to think that I could have done this myself, with the help of a couple of strong mates. But they did the job quickly and effectively. Fancy equipment was not necessary,  and they didn't need to use lasers to set anything up. They just had to take out the old part and replace the new one, and it would be in the right place if they counted the number of exposed threads.

After fixing our front door,  they were then very helpful fixing a problem with our other door. I'd already replaced the latch plate, which is definitely within my mechanical ability.

The other external door has been gradually sagging, since once again the manufacturers seem to have skimped on the part. This has meant the whole door is five or six millimetres lower than it should be, leaving a gap at the top allowing cold air to rush in.

They recommended getting new hinges, but to fix the problem in the medium term they cut out rectangular shims, and while one of them was lifting up the door with a combination of bits of wood and a crow bar, the other unscrewed the hinge and put the shims underneath. This lifted the door up, and the difference to the airtightness of the door is amazing. There are no longer icy blasts of air coming into that room, and a couple of days later it was back to the temperature in the rest of the house. Just in time for the end of winter!

​Eight weeks is a short time in housebuilding

Finally we have two working external doors.

I wrote about our unhinging problems back in May, at which point they had already been troubling us for a couple of months.

The broken top hinge was a particular worry, as our heavy front door was now just hanging on two out of three hinges, and there was a risk that another hinge would break and the door would land on somebody's head.

The people who came to install an inside door noticed this problem, and we got in touch with Wald at the end of March. I'm not sure what happened in April. It tends to be a busy month. At the end of May they put us in touch with  Yamazakiya Moko who make the best wooden windows I've seen in Japan. They visited on 5th June. They said they'd try to get in touch with the manufacturers of the window, which I suggested would not work because they had gone out of business.

As well as looking at the door problems, I showed them our more chronic and less critical big window on the South, and the leaky part at the bottom between the second and third leaf. He fairly quickly noticed that there was only one point along the bottom of these two leafs fixing the door when it was closed, and suggested that adding some more would be a good idea.

Anyway, confidence inspired, I looked forward to my front door getting a new hinge, and waited for a reply.

And waited.

I'm probably not pushy enough, and I know I'm not the most active of correspondents, but I did telephone on 18th July, and he said he was waiting for parts.

I got in touch another couple of months later, and finally got a reply back 29th September saying that without any contact from the supplier, they wouldn't be able to do anything. I wrote backing telling him that I had known the manufacturer wouldn't get back to them six months ago.

So I started exploring other routes. The two options seemed to be to find another person who could fix the door, or do it myself. So I started working out what the part was, and looking for it online.

I got in touch with the importers of our windows to see if they had any other ideas. They responded very quickly, and sent someone around. But they are importers and not fitters, so they said they'd have to get in touch with the company they worked with. Yamazakiya. I explained that I was already in touch with them, so they told me to wait for them to get back to me. October also gets pretty busy, but I wrote to the Passive House lady on 11th October. And wrote to Wald again a bit later.

On 22nd October I wrote to G-U, Gretsch-Unitas, who make these and probably a majority of high-spec window hinges in Germany, asking if they had a Japanese supplier, or if there was anywhere in Europe I could order these parts online.

The Passive House lady was in Japan, and she went to visit Yamazakiya, finding out that the problem was in getting the parts. I had assumed that getting parts would be easy. I realised that when Yamazaki had talked about the manufacturers, they were talking about parts manufacturers, not window manufacturers.

On 17th November I went to visit the Japan Home Show, where I noticed by chance Yamazakiya were exhibiting, so I went to visit their stand and had the chance for a quick chat, which I think helped remind them I'm a real person.

On 22 November I got a message from MSH Co., Ltd, an authorized distributor and the sole agent of G-U in Japan. They apologised for being so late replying to us, "since the articles in question are not treated as single parts in Japan, nor we have handled them before." But they did find part numbers, and told us we needed to specify whether the hinge was on the right or left. The good news was that they could supply the parts, but the bad news was that they could only supply 10 parts of each which would take around a month to get here, and they would charge 50,000 yen. "Please consider and let me have your reply in case you want to go ahead."

This seemed like a lot of money when I only wanted one bit of metal, but at least it explained the lack of progress from Yamazakiya.

Surely there is a way of getting this part cheaper in Europe? Well our window importer spends part of the year in Europe, and has contacts with European window manufacturers, so that seemed like a good person to get back in touch with.

By now, it's the end of January, 2018.

Once again there was a fast response, and a lot of initial positive noises although it's important to remember that Europe essentially has a four-day week because their weekend starts Friday lunchtime. I think this is an excellent thing, but it does require some concentration. I already knew that European businesses didn't do August, and you'll notice that month also missing from this timeline.

Reports then followed of potential wholesalers, parts in stock, numbers of parts required, prices, higher prices, no parts in stock, and eventually a higher price than MSH in Japan was charging for ten parts. Apparently this hinge is no longer used in Germany, and as a hinge for an out-swinging external door, it was probably rarely used in the past.

So on 8th February I got back in touch with MSH in Japan and asked how much they would charge just for the hinges and not the latch plate. I could get a single latch plate online from www.slotnodig.be, a supplier in Belgium for around 20 euros, so there was no need for me to order ten. He told me that would be 45,000 yen, but stressed that did not mean he would sell me ten latch plates for 5,000.

I reminded him that I didn't want ten latch plates, I only wanted one. And for that matter I didn't want ten hinges either.

He then seemed to get a bit defensive and told me that the maintenance and replacement of fittings should be carried out by the manufacturers of the windows or doors, because their condition depends on the quality of manufacturing, and that inappropriate manufacturing or installation will lead to elements breaking.

He also said they had to respect G-U's ''Unit Package'' of ten pcs. They had never purchased or sold this part in Japan before, did not expect to sell any in the future, and did not want to hold any on stock, and that they were giving me special treatment.

I was left feeling that the customer care at GU did not care much about customers. Also this highlighted my own unenviable situation. The manufacturer of my doors has gone out of business, so what am I supposed to do? The fact that the parts broke suggests at least a possibility that there was a problem with the quality of manufacturing, and I imagine that is the usual reason for parts needing to be replaced.

So around 9th February I ordered ten hinges from MSH, and ordered one new latch plate through www.slotnodig.be, which was great practice for my Dutch web skills. The latch plate was shipped 13th February and arrived around a week later. I was worrying that the hinges would take much longer, but they got to the MSH warehouse 19th February and were sent straight to my house.

Teaching Low Energy Building: Final Answers

Here are the answers to the final questions of my low energy building class.

1. The top priority for a low energy building is insulation.

Not solar panels, the latest electronic equipment, increasing the number of windows or planting grass on the roof. All my students got the right answer. They were 100% successful. In educational assessment terms, this question was 0% successful in discriminating between students. But I'm not so interested in discrimination. Just happy that all of my students got the main idea of the course, which is that insulation is the top priority in low energy building.

I could probably have put some tougher distractors in there, like mechanical ventilation with heat recovery, air tightness, good form factor or avoiding thermal bridging. Perhaps I should make a more difficult question next year.

2. Half the students got the next question completely right; eleven out of twenty-two taking the test.

This question did a much better job at discriminating!

This was a real-world low-energy building question getting them to choose the amount of insulation needed depending on the windows they were using. It assumed an energy budget for a small house of given surface area and floor area, and a fixed requirement of window area.

The question was made more tricky since they had to choose insulation thicknesses rounded to the nearest five or ten centimetres, as you tend to get in the real world. Also, in the real world, you need to round up rather than round down when you're trying to meet this kind of target. This may have thrown a couple of them.

Even worse is question 4  

As a language teacher, I usually despair at closed question, especially multiple choice questions where language is polarised into one correct answer and three incorrect ones. In the case of insulation, there are genuine discrete choices since the insulation comes in standard sizes. You can't buy 17.4 mm thick sheets, however much the calculations tell you that's what you need, although you could blow-fill a cavity of any thickness you like. The choices I gave in my test—15, 20, 30 or 40 cm of nano-porous super insulation—are almost a factor of ten thicker than the options given for Neomafoam by Asahi Kaisei, so I guess the choice would be something like two sheets, three sheets or four sheets thick.

Also, this was a matching question, with four different U values of window and five suitable insulation thicknesses to choose from. Obviously the eleven people who got the correct answer all gave the same answer, but the other eleven were each wrong in a different way.

One piece of low-hanging fruit was that with single-pane aluminium-framed windows, it was impossible to make walls thick enough to stay within the energy budget, and 19 out of 22 students got this bit.

At a conceptual level, the better the windows, the less insulation is needed in the walls, so the lower the window U values, the thinner the walls can be, and 16 of them got this in their overall answers, although two of them missed the answer for the single pane windows. A couple of them were choosing progressively thinner walls for higher U values, but both of them got the right answer for the single panes.

As for the other six students, it's difficult to be sure what they were thinking. They may have just been looking at the materials and assumed that wooden windows were better than PVC. They may have miscalcalated and not been thinking of the answers with top-down reasoning.

Anyway, I think the correct answers are:

• Two times thinner (around 40cm) for U 1.7 Double, low e, argon, wood frames;
• Three times thinner (around 30 cm) for 1.3 Triple, low e argon, PVC frames:
• Four times thinner (around 20 cm) for U 0.8 Triple, krypton, insulated wood frames;
• You can't make walls thick enough for the single pane windows (U 6).

3. I told you the coffee maker question before.

A one kW coffee maker in a teachers room, left on for 90 minutes, twice a day, five days a week, with a possible replacement for 10,000 yen with a thermos flask pot. How many weeks till the new pot pays for itself in electricity savings at 25 yen per kWh?

Fifteen of them got the right answer. One gave the precise answer of 26.7 weeks, but I was pleased to see most of them rounding it to the nearest week. Seven people rounded up and seven rounded down. Strictly speaking the ones who rounded down were wrong, both because rounding up is closer, and because you still haven't paid for the new pot yet. One person got half marks for giving 30 weeks. In a way, that's a better answer than the more precise 26.7. 

A couple gave 40 weeks, the shortest answer was 3 weeks, and the longest 250,000 weeks, which will take us to the year 6825. I'm not sure whether people will still be drinking coffee then.

Feedback on low energy building course

There is a well established process for running projects, and many other human endeavors, with acronyms like PDCA, standing for plan, do, check and act. Or adjust. Or again. Whatever the last A stands for, equally well established is the habit of forgetting that last bit. People love the planning, they enjoying the doing, they reluctantly dabble with checking, and have lost interest when it comes to strategic changes. The next time around, they will do things the same way, perhaps with a little less emphasis on the bits they don't like doing. But those little tweaks and readjustments are often the difference between long-term success and short-term failure. 

So this is me checking and adjusting my syllabus for the low energy building course, and I'm actually trying to use the student feedback in the same way feedback is used in control engineering rather than the frantic rush to turn down the volume you get in amateur sound engineering.

Feedback came from two directions: one in the form of paper questionnaires handed down from the university and handed out in class. For the most part students just pencil in the lozenges somewhere between strongly agree and strongly disagree, but I encourage them to fill in the spaces for written comments. In one class I told them they should write something about the paper questionnaires being a waste of time, and the university should administer them online. Four of the students did write something like that, and while I was pleased, it shows that students in the classroom will just write what the teacher tells them to, which is just one of the reasons paper questionnaires should not be completed in class. 

That was a different class though. In the low energy building class, their comments mostly just
reported that they had learnt about low energy building. Important knowledge about low energy building. Knowledge about the importance of low energy building. A couple just said they learnt about buildings, which is perhaps an even better response. One person said it was important to think about economic issues as well. Another valued the fact that the lesson was in English. Most of these comments (70%) were in Japanese, the same language as the university questionnaire, but nobody commented here that I should speak more Japanese, or that the class should not be in English. 

The other formal avenue for feedback was in the final questions, where I asked them these two questions:

• What was missing from the course? What other topics should have been covered, or what topics should have been covered in more depth?
• How can the course be improved? How can I make it better for next year? 

I know the pedantic grammarian will find four questions there, but I rephrased each question to make it clear what I wanted to know, and also because the length of answer is often proportional to the length of the question since the human tendency for mimicry is much stronger than the tendency for following instructions. Almost all of the students (90%) answered these English language questions in English.

Six of them mentioned language in their suggestions for improvements. Three suggested I should speak more Japanese, one saying an all-English class was a bit difficult. One suggested adding definitions in Japanese on the slides. Two wanted the students to speak more English, one of them suggesting students should only speak English in class, the other saying her English had become more fluent and that I should continue to English. 

Conclusion on language: Using theories to determine thermal comfort in buildings, it seems the language temperature of the room is OK, judging by the relatively small number of people who are too hot or too cold. Adding definitions in Japanese to the slides is a great idea that I need to do more.

I was worried that I'm doing too many calculations, but it looks more like the opposite. Seven people mentioned calculations, mostly wanting more time to do calculations, or wanting me to spend more time on them. They mentioned U-values, windows, compound insulation and calculating whole-house U-values.

In terms of course content, four wanted more case studies, one asking about low energy buildings in Matsumoto, and two wanting more information about low energy buildings in other countries or about international differences.

Three wanted to know more about insulation materials.

Two mentioned cooling, which I know is an important topic that I should have covered. I just realised that lesson 5 started off as a lesson on cooling, but now seems to focus mostly on comfort. I think the windows from the previous lesson may have spilled into it. Also I had prepared a full lesson on cooling, which I then did not teach.

Two wanted to know about the latest technology, one asking about the latest building techniques, the other giving the example of dye sensitized solar cells.

Other content suggestions were for Passivhaus in more depth, hydroelectricity, window frames, and large scale energy savings, for example at the city scale.

​Other comments were ​more about the delivery and presentation of the class.

Four people gave positive comments on the course​:​ that it was great, perfect, nice, or had a good balance.

Three people gave somewhat critical comments: I should make my slides better, I should ask what students want to know, and I should introduce an expert on low energy building to the class.

Actually the last one is probably not critical, and I should take it as a positive suggestion, and in fact a really good idea. They may mean that I should be talking about low energy building experts rather than physically introducing one in the classroom. Just because that's how I would have written "you're crap" doesn't mean that is what they meant when they wrote it. While it's great that so many of them are writing in English, there is more chance for ambiguity when they are writing in a foreign language.

(I didn't have this question)

One student suggested that the range of questions in the online tests was different to the content of the class.

One person suggested I should always give measurements for the sizes of windows and rooms. I think this is something I realised half way through the semester, and something that made me think I would get requests for fewer calculations. I tend to give the students real world problems, and hope that they will be able to grasp the problem, identify what information they need to solve the problem, get exact values for the information where they can, and estimate where they don't have exact answers. This is a chain and is only as strong as its weakest link, and most of the students will fall down at some point. What I need to do is to break problems down in a much more systematic way, and give them several chances to practice each step before putting the steps together. I need to carry on giving them guesstimation problems, for example estimating the dimensions of walls or windows, but not at the same time as giving them thermodynamics problems.

Another wanted a list of formulas which we learn in class, which would be a really good idea. I should produce a low energy cheat sheet!

Another suggested that presentations should all be done in one lesson. Interestingly this was from one of the students in the group that went up to speak first, who had specifically said that they wanted to give their presentations in that lesson, a week before all the other presentations.

Finally, there was a comment that I should "distinguish between good and weak students in good balance". I'm not sure what that means. Perhaps that I should be making sure I'm teaching the students at the right level. Perhaps it means they should be working together in groups based on their level.

Now it's back to the drawing board for next year's class! The syllabus needs to be uploaded next week.

Teaching Low Energy Building: Final Questions-part one

Each week ​I've been adding questions on the content of each lesson to an online learner management system called Module. Here are the​ first three​ questions for the final lessons. I'll post the answers next week!

1.​ ​What is the top priority for a low-energy building?

Select one:

Add solar panels

Buy the latest electronic equipment

Increase the number of windows

Plant grass on the roof

Use insulation

​2. ​(This question follows the question in the Windows 2.0 quiz)

You want to build a small house with a heating load under 25 kWh/m2a. The house is 35 square metres, so you want to use less than 875 kWh per year. The wall and roof area of the house is 100 square metres. You want 4 square metres of windows. The house is in Matsumoto where the annual heating demand (G) is 80 kKh (kilo kelvin hours).

If you use U 2.3 windows, they will lose 736 kWh per year. So the rest of the house must lose less than 139 kWh (875-736). The U value of the walls must be 0.017. (U = Q / A G.) Using nano-porous super-insulation material (k=0.015 Wm/K), these walls would be around 90 centimetres thick!

If you use the other windows, how many times smaller are the U values for the wall?

In other words, how much thinner can the walls be?

U 1.7 Double, low e, argon, wood frames	Choose...three times thinner (around 30 cm)five times thinner (around 15 cm)two times thinner (around 40 cm)four times thinner (around 20 cm)you can't make walls thick enough
U 1.3 Triple, low e argon, PVC frames	Choose...three times thinner (around 30 cm)five times thinner (around 15 cm)two times thinner (around 40 cm)four times thinner (around 20 cm)you can't make walls thick enough
U 0.8 Triple, krypton, insulated wood frames	Choose...three times thinner (around 30 cm)five times thinner (around 15 cm)two times thinner (around 40 cm)four times thinner (around 20 cm)you can't make walls thick enough
What about the single pane windows (U 6)?	Choose...three times thinner (around 30 cm)five times thinner (around 15 cm)two times thinner (around 40 cm)four times thinner (around 20 cm)you can't make walls thick enough

​3. The teachers' room has a coffee maker. Usually five days a week, twice a day, someone makes coffee in the break time, has one cup. Then for 90 minutes the rest of the coffee sits in the pot, with the heater on, until the next lesson has finished.

The coffee maker uses a 1 kW heating element to keep the coffee warm.
There is a new coffee machine with a thermos flask pot. It does not need a heating element.
It costs 10,000 yen.
Electricity costs 25 yen per kWh.
If we buy the new coffee maker we will pay less money for electricity.

How many weeks will it take to save the money?


Answer:

​

Future predictions

Here are some predictions based on current trends.

Computer chips will have one transistor per atom in 2025.

Every car will be electric by 2053.


There will be enough solar panels to cover all land on earth by 2056.

Two of these predictions are very likely to be wrong.

The first is based on Moore's law, which predicts that the number of transistors on a given size of chip will double every eighteen months.

The figure for electric cars is based on the recent increase in proportion of EVs, which in most countries is still less than one percent. The proportion may increase exponentially, and will of course stop increasing when it reaches 100%.


The figure for solar panels is based on a compound annual growth rate of 30%, which has been been happening for the past twenty years. I'm assuming that power output per area of solar panel will stay the same, which it probably won't. New panels will steadily produce more electricity for the same area, but the increase will not be large, let alone exponential.

Of these predictions, I think Moore's law is the most likely to come true. This law has held true for fifty years. I don't think atoms will necessarily stop it, since quantum computing is now a thing.

Moore's law has been enabled by the success of electronics leading to a steadily increasing budget for development of ever smaller chips. Developments have tended to compliment each other, rather than replace them. The budget is not increasing at a Moorean rate though.

These exponential growth rates are usually unsustainable since at some point they are limited by physical constraints of the real world. If things are getting smaller, of course, there is no limit. Right now there is a limit to our understanding of the very small, but if science shows us one thing it is that when we ask questions, sooner or later we find answers. The harder we look for the answers, the quicker we find them.

More interesting is Wirth's law, which states that "Software is getting slower more rapidly than hardware is getting faster." So all these improvements in the computer power are eaten up by extra complications and functionality that we don't necessarily need. I noticed this around 1992, and decided to stop spending so much time programming computers. I now wish I'd written a paper on it, like Dr. Wirth.



I'm pretty sure solar panel production will peak before we cover the whole planet, although I will not be surprised to see nature reserves clear cut for solar farms, massive floating arrays, or increased solar installation in space. They may even start making the panels up there. The economic effects of increased solar power will likely be that some electricity is effectively free, which will drive down the price of electricity, and reduce the value of the panels, making their manufacture less worthwhile. So I don't think this prediction will come true. I'm hoping to still be alive, and will be able to find out.

There will very likely be a point in the future when the only people not driving electric vehicles are stupid and rich, and I think this point will come sooner rather than later. By the time our computers are firing on subatomic logic, the majority of people will be buying new electric cars. I'm sure this will sound as ridiculous as someone predicting the wide use of steam trains in 1818, or motor cars in 1918. Also, we must not underestimate the size of the stupid and rich demographic, and its disproportionate political power. There will always be a bit of liquid fuel sloshing around, and we are unlikely to ever have 100% electric vehicles, but I think we'll be close to that long before 2053.

Here's an article from the Guardian about accelerating car sales. Here's another claiming that the electric vehicle revolution in Australia is stuck in first gear. The press is never shy to use motor-industry metaphors, but they don't realise EVs only need one gear. Also they may never have experienced the excellent acceleration of electric vehicles.

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".