Thursday, 26 April 2018

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:

Monday, 19 March 2018

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!

Tuesday, 6 March 2018

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!

Sunday, 25 February 2018

​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, 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, 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.

Friday, 16 February 2018

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.