23 Feb 2010

Dickon Robinson

Monday evening spent at the Cambridge Forum for the Construction Industry, and an event called Assisted Selfbuild (an alternative approach to housing provision). Of the three speakers, the one that caught my ear was Dickon Robinson, pictured here, well-known as the one-time Development Director of the Peabody Trust and therefore someone very involved in commissioning various MMC projects over the past decade or so. He is still heavily involved in the politics of housing through various bodies such as CABE.

What caught my ear in particular was one or two questions he posed. He didn't exactly say that the government's housing projections were a load of crap, but he did raise the issue of whether it was really such a wonderful idea for more and more of us to be living alone. "Living in single person households is inherently unsustainable" is one quite I wrote down. Another is "It may be that we already have enough homes." Finally: "Let's extend existing homes rather than building such small new ones." This was backed up by some stats: the UK now builds the smallest new homes in Europe (I guess many of you already knew that). But more. 100 years ago, our space standards were much better, but much of this old housing stock is now occupied by empty nesters and the occupation density is very low. But no one in the housing debate has talked about occupation density; instead the talk — and policy — has all been around housing density. They are not the same thing. I think it's a point well made.

Robinson was of the opinion that everyone who extended or renovated an existing house should be described as a selfbuilder, thus making the definition far wider than is normally accepted. And he went on to say that one of the reasons for the enduring popularity of older houses was that they were inherently adaptable and extensible, whereas today's offerings are very difficult to alter. He also made some interesting observations about social housing, particularly so as he has been so intimately involved in it at Peabody. He recalled that the original council houses, built in the 20s and 30s, were only available to people who had jobs, and that they were regularly inspected by council officials to see that they were being properly cared for — these selection criteria were relaxed after WW2, when many families had to be rehoused. He then suggested that for some, social housing had become "deeply dis-empowering" because tenure was secure, rents were low and thus it "stopped you having to get up in the morning." He also spoke out against pepper-potting, the current practice of mixing affordable with private housing, the logic being to avoid building ghettos. He thought it hadn't been a great success and that, by and large, people were happier living with neighbours of similar social standing. Interesting thoughts, running counter to the prevailing mainstream for sure. The last of the great paternalists? Or a breath of fresh air in a sea of political correctness? You decide.

19 Feb 2010

Whither the Wood Burning Stove?

On Wednesday this week I travelled down to Exeter to meet Stovax, making good a promise I made to them six weeks ago. I really new sweet FA about Stovax, other than they made wood burning stoves, and I quite expected a couple of beardies wielding hammers and tongs. How wrong I was. It's now a substantial concern. The business started in 1981 when Guy Brook and his friend Miles Jennings began firstly importing and distributing stoves and then making Victorian fireplaces and surrounds. It's been been expanding ever since, some of it by starting up new companies to produce fireplace products, some by acquisition of related businesses. Stovax Holdings now employs 450 people and has become the largest stove maker in the UK. The business includes several brands: Stovax, Yeoman, Gazco (makes gas fires - does well), Redfyre (ranges) and there is another, now separate, holding company which contains a tiles business called Original Style. "In fact everything to do with fires except hearths," explained Greg Taylor, the technical director.

Greg, it turned out, is in the middle of a selfbuild and he had spent much of the past few months buried in the Housebuilder's Bible. He brought along his copy and it was marked up with post-it notes. My first thought was that I was being ambushed, and that I would be forced to work in the foundry for the next six months until I saw the error of my ways. But of course he was sweetness and light, and actually very helpful as well. I learned a lot from him during our lengthy interview.

Like what exactly?

• The difference between a wood-only burning stove and a multifuel stove. Wood burns best when laid on a bed of ash with air being injected at it from above. In contrast, coal burns best in a grate with air coming from underneath. Wood will still burn in such a grate but not as well. So a multifuel is basically a coal grate, whilst the wood grates are rather different and would be hopeless for coal. Stovax have seen sales of wood-only stoves rise steadily over the years and now they sell pretty much 50/50 (wood v multifuel).

• Solid fuel stoves can get to around 80% efficiency, but anything beyond this is technically difficult because heat is needed to keep the flue operating well.

• Virtually no one burns straight coal anymore but there are any number of clean or smokeless coals. Anthracite is a naturally occurring coal that burns very clean, but it isn't widely used these days. Instead we usually use manufactured smokeless coal pellets, known as Ancit.

• The Clean Air Act is the legislation behind a number of Smoke Control Areas where it is not permitted to burn wood or coal. You can burn smokeless fuels such as ancit, but if you want to burn wood, you need to get a stove that meets the technically demanding PD 6434 standard, which DEFRA test for in Cheltenham. These "cleanburn" stoves are then passed for use in Smoke Control Areas. It's not an easy test to pass, the cost is around £8,700, and Stovax are currently putting a lot of their stoves through this test. The more efficient a stove is the less smoke there is. "Smoke is unburned fuel" I have noted down: QED the more efficient the stove is, the more of the wood it burns and the cleaner the resulting smoke is.

• One of the keys to getting the best out of a cleanburn stove is to burn dry wood, Greg recommended getting a moisture meter and making sure that you don't burn logs with a moisture content no greater than 20%, preferably 15%. He said in order to get a true reading, split the log open and apply the meter to the middle.

• We are not about to run out of wood as a fuel. There are currently around 285,000 domestic wood stoves installed into the UK, burning around one million tonnes of timber in total each year (that's nearly 4 tonnes each stove, which seems a lot). The Forestry Commission reckons we are have the potential to burn ten times as much timber before we run into capacity constraints. They have in place a "Woodfuel Strategy for England" which should release and additional 2 million tonnes each year by 2020. Which means we are going to have to buy an awful lot of woodstoves in the next ten years if we are going to consume all this extra timber. OK, I know a lot will end up being burned commercially, but still the domestic sector will have a significant role to play.

• Stovax spent three years trying to sell pellet boilers, but the interest was minimal. They have now abandoned the technology (for the time being) and are concentrating on wood-fueled boilers, like....

• The Stockton HB. These are designed to heat hot water for the cylinder and for a number of radiators, but they are still very much focal-point room fires, unlike the utilitarian pellet boilers which ideally need to be sited in a basement. I got shown the labs where they were testing a Stockton 14. At full pelt, it burns 6kg of dry wood an hour but this belts out 14kW to heat hot water for rads and 8kW out of the fire itself and into the room.

• Greg Taylor (pictured here with the Stovax Studio 2 in the test lab) was keen to emphasise "link up." Link up? It involves adding a woodburning boiler stove to an existing central heating boiler system. The system, through gravity and series of valves, is set up so that the gas or oil boiler switches off when the stove is lit and vice versa. “Link up” allows homeowners to maintain the convenience of a conventionally fuelled boiler whilst also dramatically reducing fossil fuel bills through the use of solid fuel as an extra source of heat and hot water.

“When you get up in the morning or come home from work in the evening, the conventionally fuelled boiler can have warmed your home and given you plenty of hot water. As soon as you have the stove lit, the boiler can switch off until it’s needed again. Add solar panels and your conventional gas or oil boiler will be used even less.”

• There was a sub-text going on here which we didn't really have time to explore, but which struck me afterwards. There is a subtle difference here between a boiler and a stove. You don't really want a boiler in your living room, something I know from personal observation, having stayed in a house with what claimed to be a "pellet-stove" in pride of place next to the TV. It was noisy, ugly and just plain mechanical. So anything which ranks as a "biomass boiler" is only ever going to be of interest to a rich minority who have utility rooms and/or basements, whereas a wood-burning boiler-stove appeals to a much larger grouping. What Stovax are aiming at doing is building kit which looks like a stove and yet acts like a boiler.

• Which brings us back to the Renewable Heat Incentive which is proposing to exclude wood burning stoves but to include pellet boilers at a deemed tariff of 9p per kWh for 15 years. The worked example (on page 50) suggests that this subsidy would be worth over £1,000 a year, £15,000 in total. The logic behind excluding wood stoves is explained on page 31: These present difficulties as it is extremely difficult to monitor how much they are used (they are usually a secondary source of heat, the use of which will be optional), and to what extent they are used with renewable fuel rather than, for instance, coal. Now this second objection could be addressed by making the Stockton and its ilk wood-only rather than multifuel, but the first objection is much harder to address, especially if Greg's linking theory is put into place. Whereas the consumer seems to be saying "we want stoves, not boilers" the subsidies are going to go to the boilers. But, as we have already established, pellet boilers are really only ever going to be of interest to people with relatively large houses.

• In fact exactly the same thing can be said about ground source heat pumps which generally require large gardens. The RHI would seem to be a very generous subsidy for already wealthy people. Next week, I am booked into the government's Renewable Heat Incentive workshop, and I expect some heated exchanges on this very topic. But I digress. the subject of this ramble is wood burning stoves, and this leads us onto...

• We discussed airtight houses and how wood-burning stoves might cope. In theory, it is possible to create room-sealed wood-burning appliances (just as balanced-flue gas-fires and gas-boilers are). In practice, it hasn't happened yet, although Stovax sells optional kits for many of their stoves to take external combustion air directly to the appliance. Current UK regulations (Part J) require that there must be an additional supply of air from inside the house for any stove over 5kW but as houses become tighter this regulation will need to change for new houses. Wood burning stoves do not yet have an agreed technology to make them fully room-sealed. There are some room-sealed prototypes being made in Germany but nothing yet in commercial production. So the future of wood-burning appliances in near-Passive House standard homes is as yet uncertain, but at the moment, if you aspire to build a Passive House, you can't have a stove in your living room.

• We touched on the issue of ventilation and just how complicated it is becoming. Apparently, wood stoves tend to work fine when the house is under positive pressure, but react badly to negative pressure. This makes sense, doesn't it? So designers of ventilation systems need to be aware if a wood-stove is planned.

I hope this is a helpful guide to where things stand re: woodburning stoves. It's not a topic I have any great expertise in, and I welcome feedback from anyone with something useful to add.

16 Feb 2010

Was Rome like this in 409 AD?

I have been watching the whole ClimateGate fiasco with a sense of bewilderment. This time last year, there seemed to be broad consensus amongst intelligent people that anthropogenic global warming was real. At least as real as other great scientific theories like evolution and plate tectonics. As Real Climate put it yesterday: The system we study is ruled by the well-known laws of physics, there is plenty of hard data and peer-reviewed studies, and the science is relatively mature. The greenhouse effect was discovered in 1824 by Fourier, the heat trapping properties of CO2 and other gases were first measured by Tyndall in 1859, the climate sensitivity to CO2 was first computed in 1896 by Arrhenius, and by the 1950s the scientific foundations were pretty much understood.

I don't know about you, but I kind of trust "broad scientific consensus." Because of it, I have a warm home this morning, I am well fed and have been all my life, I have light and my computer works, and you can read this message. If science tells me that plate tectonics causes earthquakes and that we have (as yet) no control over this phenomenon, I am inclined to believe. And if science tells me that the amount of CO2 in the atmosphere has an effect on the surface temperature of the Earth, I am also inclined to believe. Unlike plate tectonics, atmospheric CO2 is something we have control over (in theory at least) and that is also something that it is hard to argue with.

But in the past few months, we have seen an extraordinary anti-scientific backlash against the mainstream consensus. I don't know how well organised it is, but it's been very effective, and now the right-wing press has taken up the baton (sensing some sort of popular revolt) and is now daily peppering the climate scientists with a few well-aimed blows to the midriff. Sunday's piece in the Mail, re-writing a BBC interview with Professor Phil "CimateGate" Jones is a case in point. In the original interview, Jones seems to be a little too candid for his own good and admits to problems tracking all the data sets, and problems in understanding the Medieval Warm Period. The Mail reporter, Jonathan Petre (presumably acting under orders?) comes on like a barrister at a show trial, using these comments to paint a very different picture. But if you read the article closely, it's almost all innuendo.

Data for vital 'hockey stick graph' has gone missing. So what? It doesn't make the hockey stick wrong.

Warming periods have happened before - but NOT due to man-made changes. So what? It doesn't mean that man-made changes won't affect the climate in future, does it?

Petre of course isn't trying to win an argument, because there isn't really an argument. No one is putting forward a plausible counter theory (the few sun spottists dishonourably excepted). All he is hoping to do is to lodge a few sceptical bon-mots into the heads of the blokes at the bar in Rose & Crown, link it to a fear of government intervention and rising taxes, and cause a general revulsion to a theory that spells bad news for us all. And it's working a treat. More people than ever are sceptical about global warming, and what the right-wing press have managed to do is to link it all up as a left-wing conspiracy. If Friends of the Earth, Greenpeace, WWF and the BBC all say it's real, then it must be a lie!

Whilst the sceptics are very astute at "uncovering" discrepancies and conspiracies, what they haven't managed to do is to challenge the basic theory. If we keep pumping vast quantities of CO2 into the atmosphere, we are going to cause some mighty ruptures up ahead. That's it. It's that simple. Arguing that "climate change is a natural phenomenon, its been happening for millions of years" rather misses the point. It's us and in particular our civilisation that is unnatural, and it's been based on a relatively brief interlude of mild climatic conditions, and if we upset this particular applecart, it's not the Planet we need to be worrying about, but ourselves and our comfortable lifestyles. There's nothing left or right wing about this.

What is going on now is all very sad. It's turning into a witch-hunt. Normally obscure figures like Jones, and the guys that write RealClimate, are under attack in ways they can never have anticipated, and all because they are telling us things we would rather not know.

And if the Daily Mail is bad (it is), then the Express is worse. And even the Telegraph and the Times have succumbed to the new mood. And if you read the comments (hundreds of them) that always follow on from these articles, you realise that they are indeed responding to a popular mood, a growing sentiment that all these scientists are just scam artists, and the government is going along because it just wants to keep raising taxes. These people sound so angry, just like a lynch mob.

Here's a not atypical response from Derek J of Chester-le-Street (in Mail on Sunday)

BUT will the Greenie's admit it will they Hell
all that extra Money will all payed out to line the pockets of Al Gore, etc, etc, etc.
its not a case of we put our Heads in the Sand
BUT MORE A CASE OF YOU LOT PUT YOUR HEADS IN THE CLOUDS and couldn't or more to the POINT WOULD LISTERN To Anyone other than your Messiah's who have all turned out to be FALSE

I've been hesitant to use that awful word denialist, but I have known one or two alcoholics and the similarities are striking. The anger, the indignation, the persecution, the justification. "There's nothing wrong with me mate, it's you who are a total fuck-up, leave me alone." It's usually followed by a punch and the sound of breaking glass.

9 Feb 2010

Thoughts on the Renewable Heat Incentive

Heat pumps
On p31 of the consultation document, it states that only efficient heat pumps will be permitted. However this ignores the fact that the efficiency of a heat pump is related to the work it is being asked to do, and not simply the manufacturing standard. The standard CoP (Coefficient of Performance - the higher the figure the better) figures used by heat pump manufacturers refer to an uplift of 35°C. For every 1°C above this that the system is required to deliver, the efficiency of the heat pump system reduces by around 3%. Therefore a heat pump may have an efficiency of 4.0 when delivering hot water at 40°C (suitable for underfloor heating) but this will reduce to less than 2.0 if used to heat radiators at over 70°C. If the published efficiency of the heat pump starts at 3.0, then the actual efficiency is likely to fall below 1.5 if used to heat conventional radiators.

A heat pump needs to perform at a CoP better than 1.5 in order to match the carbon output of an A rated oil fired boiler.

As it stands, this incentive will cause oil-fired boilers (as a technology) to be abandoned, without any clear justification. Many people with radiator-based central heating systems looking to replace a boiler will be tempted to switch to a heat pump solely because of the incentive, which looks like it's going to worth around £750-£1,000 a year for 18 years. And yet, unless the heat delivery system is changed (which is unlikely because it would be expensive and disruptive), the energy and carbon burned will actually increase, compared to an A rated oil-fired boiler. For this reason, air source heat pumps, in particular, are ill suited to replacing domestic boilers. There seems little logic in incentivising people to install them instead of efficient fossil-fuel boilers.

Bearing this in mind, why shouldn't this incentive scheme be extended into areas where it has the capability to make a much more meaningful contribution to reducing carbon emissions? How about extending it to people undertaking significant energy efficiency upgrades, way beyond topping up loft insulation and adding cavity wall insulation? The cost bringing a 20th century (or older) house up to modern standards (something akin to the Passive House standard for refurbishment, or Energy Savings Trust A rating) is far greater than the cost of installing a heat pump. Estimates vary from around £12,000 up to £40,000 (if glazing is to be included as well). The carbon savings are also much greater, however there is no financial incentive other than making savings on fuel bills. As it stands, the payback on this type of work extends to many decades.

The UK Green Building Council is putting forward a Pay As You Save Scheme, whereby lenders will be encouraged to make loans to undertake such improvements and in exchange the repayments would be paid for from the savings from lower fuel bills. Such a scheme enjoys no official backing as yet. Why not add some element of subsidy to it by adding such refurbishment to list of "technologies" which the Renewable Heat Incentive is designed to reward?

8 Feb 2010

House 2.0 meets QI?

Here’s a vaguely interesting question. Which is worth more: the UK stock market or the UK housing market?

The housing market wins. It’s aggregate total value is somewhere around £4 trillion, somewhat over twice as much as the stock market. A trillion is 1,000 billion, which is itself is 1,000 million.

The value of the stock market can be checked here.

The value of the housing market is a bit more hazy, but by taking the rough number of houses (around 25 million) and multiplying them by the average value (£163,000 according to Nationwide) gives you an answer around £4 trillion.

The gilt (government debt) market is currently worth £700 billion - that’s £0.7 trillion - doubling in the past four years. It’s still a tiddler compared to property and equities, but then again it’s a mortgage, not a store of wealth.

You want more of this? Try comparing the value of individual companies to the value of housing in towns and cities. Our largest company (by market capitalisation) is HSBC which is currently worth £112 billion. That’s equivalent to 700,000 average homes, enough to house a city of 2 million population - say Greater Manchester. Of course, property in Manchester itself would be worth far more than the sum total of its housing stock, but then I’m not considering commercial or council property values here.

The 100th biggest company listed on the UK stockmarket is currently Thomas Cook, the travel agent. It’s value is £1.9 billion, equivalent to around 12,000 average houses, or a the housing stock of small town with a population of 30,000.

3 Feb 2010

More on Feed-in Tariffs

Yesterday I had the pleasure of reading through the two documents that the Department of Energy and Climate Change put on their website on Monday (Feb 1st). The first was the government's response to the Feed-in Tariffs consultation, which sets the rates for the tariffs for electricity generating technologies, principally PV, wind, hydro and micro-CHP. These feed-in tariffs are due to come into effect this April, but will apply to anyone who has fitted one of these technologies since July 2009, when the decision to switch to feed-in tariffs was made. There are no major changes to be found in the finished document, though the rates have been adjusted a little.

Feed-in Tariffs
What these feed-in tariffs essentially do is strip away the initial capital subsidies which have existed up till now and replace them with annual payments based on how much electricity you have produced. The amount depends on the technology. PV is very expensive to install and therefore gets a high rate of return, as much as 41.3p per kWh for 25 years for small retrofit installations. MicroCHP is much cheaper and therefore attracts a smaller subsidy — 10p per kWh for just ten years. The payments will be index linked. The amount you get paid will depend on what your meter says you have produced. You don't have to export all or any of this electricity to the grid, but if you do, you will get an additional 3p per kWh for your pains.

You'll have to sign a contract to say that you will keep the plant in good repair, and if you sell up and move house, the new owner collects the Feed-in Tariff. The rates paid are guaranteed for the duration of the contract, so in some respects this is a bit like buying index-linked gilts. How does it compare as an investment?

There is a worked example on page 33 showing how it might work with a small PV unit retrofitted onto a detached house. It assumes production of 2,000kWh per annum from the PV array on a house consuming 4,500kWh per annum. The income comes in via three different methods
1. The 2,000kWh produced by the PV attracts 41.3p/kWh or £826 per annum
2. It is assumed that half this amount is exported to the grid, which attracts an additional 3p/kWh or £30 per annum
3. The other half is consumed in the house which saves having to buy 1,000kWh at 13p/kWh from the electricity supplier, a saving of £130.
Combine these and the total income is £986 per annum. The question is, how much would this all cost to install? You'd probably need at 3kW system in order to generate 2,000kWh/annum - depends of course on your location and orientation. That's around 24m2, and the cost would be around £20,000 to install. So that's a return of around 5% for your investment (i.e. £1,000 a year for a £20,000 investment). With index linked gilts currently yielding just over 2%, that leaves three/fifths of the payment/savings to cover writing off the capital cost of the installation. That's £600 a year for 25 years = £15,000. That's not incredibly attractive, but it should be relatively safe. In theory, these contracts should be as safe as gilts (which are said to be the safest of all investments because they are government guaranteed), but in practice a future government might renege on the contract if it became politically expedient. An in addition, there would be added costs not factored into the equation. Servicing for one, insurance for another. With PV costing rather more than lead, there must be a risk that the arrays would get stolen, or may get damaged by hail or vandalism. There is also the issue of whether or not installing renewable technologies in the home really will add to the capital value of the house when you come to sell.

So the feed-in tariffs are an improvement on the lacklustre capital subsidies that have existed in the UK up till now, but they are still not the sort of eye watering investment opportunity that will get the City Boys throwing up PV on their roofs to make a quick buck. In reality, this is still only going to appeal to enthusiasts.

Having said that, I met one in Switzerland last week who had bought 800m2 of PV and installed it himself on the roof of a cattle shed belonging to a nearby farmer. 800m2! That'll be nearly a million quid's worth. And all because of their feed-in tariff.

Renewable Heat Incentive
The second document is the consultation for the Renewable Heat Incentive, which is similar to the feed-in tariff but for heat producing technologies, principally solar thermal, heat pumps and biomass boilers. It once again comes with a table of tariffs:
• Solar thermal to get 18p/kWh for 20 years
• Air source heat pumps to get 7.5p/kWh for 18 years
• Ground source heat pumps to get 7p/kWh for 23 years
• Solid biomass to get 9p/kWh for 15 years

There are some major differences between these subsidies and the Feed-in Tariffs. Firstly, the output of the units will be assumed rather than metered. Their word for it is deemed. This to me immediately presents a major problem, because it will be assumed that the installations will be working as designed. A lot of cheap and inadequate systems may end up being installed in order to harvest the subsidy. And, in particular, heat pumps may get installed into poorly insulated homes where they will not really be up to the job in hand.

More on this soon, but if this incentive scheme comes into effect (on the projected date of April 2011) it will effectively sound the death knell for conventional oil fired boilers which are already struggling to compete with heat pumps. This scheme will grant you around £1,000 a year for installing a heat pump. There is one ray of hope for the oil fired boiler makers and that is called FAME, which stands for fatty acid methyl ester. It's a biofuel produced from vegetable oil which can be blended with heating oil for use in domestic boilers. The paper suggests that an oil boiler could be converted to burn FAME and therefore obtain a subsidy, but details here are sketchy.

2 Feb 2010

The Green Bling Tariffs

The Department of Energy and Climate Change has now published the final version of the Feed-in-Tariffs which are due to come into effect in April. The document is here. It has also published consultation, including indicative pricing, on the second leg of this subsidy, the Renewable Heat Incentive, which covers heat pumps, solar thermal and biomass.

I have yet to work out the full implications, but I suspect that the Renewable Heat Incentive will tilt the balance firmly in favour of heat pumps for anyone considering how to heat a house.

1 Feb 2010

36 hours in Switzerland

Last week I went to Switzerland on a big shiny Airbus as a guest of Just Swiss. I went with two esteemed architects, Meredith Bowles and Roger Zogolovitch (pictured here in the snow, Roger on the left) and we were shown round a site of ultra low energy apartments called Silence, a window factory, two houses under construction and a very state-of-the-art factory timber frame housebuilder called Schoeb. All very interesting stuff, and the Swiss we met were incredibly enthusiastic and, well, just plain nice. It snowed heavily and it all looked like a winter fairy land. Great trip, great way to spend 36 hours in January.

Meredith and Roger were looking at potential partnering arrangements with Schoeb and had a couple of rather more detailed discussions than me. I got a more personal tour, showing how this business had grown from a joinery workshop in Walter Schoeb's garage to become Switzerland's most successful factory house builder, completing around 60 units a year. That's still small by German standards, but compares in scale with UK housebuilders like Oakwrights. Their semi-automated production lines were humming away with Hundeggers and Weinmanns beavering away — I have seen a few of these operations now — with just two or three people overseeing the construction of walls, floors and roof panels. Schoeb are interested in building in the UK and have set up an office in London. They will also be at EcoBuild as part of the Just Swiss stand, so if you want to find out more, check them out there. My impression was that their system is very robust, very well thought out, but may prove to be rather too expensive for the typical UK client. Only those wanting quality — or perhaps a Passive House solution out of a box — need apply. Interestingly, the cost of shipping from Switzerland to the UK only adds around 5% to the factory gate prices: the heaviest component is the timber which has to be imported into the UK in any event.

Some random points of interest. The Swiss have their own energy saving performance standard called Minergie. It comes in various format. Standard Minergie, Minergie P (roughly equivalent to PassivHaus), Minergie P Eco (with other sustainability features like water saving) and Minergie P Eco Plus (with added renewables). Obviously, this system is never going to be of interest to anyone other than the Swiss; it's all rather like the Code for Sustainable Homes in this respect. Yet another reminder as to how good it would be to have a supra-national standard that everyone could understand.

Switzerland seems to be in love with heat pumps. But then their electricity is relatively low carbon, with a mix of nuclear and hydro, including some pumped storage schemes — they do seem to have rather more hills than we do here in East Anglia.

The low energy apartments, called Silence, featured something I hadn't seen before. Phase change glass. GlassX is the name. Apparently, the architect of the apartment scheme, Dietrich Schwarz, happens to be the CEO of GlassX, and therefore has the wherewithal to specify his product because he is the architect. Does this strike you as a little bit unusual? Or maybe that’s usual in Switzerland.

And on the visit to window manufacturer, Scheiwiller, I saw my first bit of quadruple glazing. Here's my picture. No drooling over the 0.2 U value glass please. The Swiss really seem to be having a love affair with huge patio doors and in the Scheiwiller workshop, there was a beast that was 5m long and 2.3m high, triple glazed and weighing in at 400kg when glazed. It is so big that it will have to be re-glazed on site because it won't be possible to lift in into place with the glass in. I'm not sure such enormous glazing units are really such a good idea. The MD of Scheiwiller told me that triple glazing first appeared in his workshop in around 2004 and it has grown steadily since then. Now around half of all his work is triple glazed, and he sort of expects it all to go to triple before long. Hence the appearance of quadruple glazing.

Schoeb the housebuilders rather confirmed this trend too. Generally, their basic spec involves double glazing and no ventilation at all (they open the windows instead when things get stuffy). But the green spec almost always involves triple glazing and mechanical ventilation with heat recovery. It seems that triple glazing is almost a marker for a mechanical ventilation — where you have one, you have the other.