30 Jan 2008

On Thermaskirt

Guys, guys, guys. It is a really interesting product you've come up with here. But why the legs? Yes, I know it catches a man's eye, but it also sends a reverse subliminal message. A what? It says to me that you'll be hoping that I'll be so bowled over by the girl's legs that I won't notice the wool being pulled over my eyes. I appreciate skirting heating may not be the easiest sale in the world, but do you have to resort to the world of Loaded and Nuts. Maybe it's my age, but I find this sort of advertising a real turn off.

Adrian, you mean like this?

In my opinion, it would look better if you rotated it through 90 degree - most of the text you'd want to read is vertical in the current version.

28 Jan 2008

Window costs

I have been compiling a survey on window buying and have managed for the first time to produce the essential cost information as a graphic. I hope to be using this technique a whole lot more in the future. I'd be interested to know if it's both legible and comprehensible.

25 Jan 2008

Caroline Flint, the new Housing Minister

So it’s farewell and good luck to Yvette Cooper and hello and good luck to Caroline Flint (pictured) who has just been appointed as her replacement as Housing Minister. I’ve laid into Yvette a few times in this blog over the past few months, as the minister is the embodiment of the government’s misguided housing policy, but she did at least know her onions, even if she was restricted as to what she could say or do. But now we have a new minister who knows nothing about what has been going on in this field and will presumably take months to get up to speed. And all because Peter Hain tripped up over his campaign donations. I know this is pure cliché, but it does seem like a strange way to run a government

23 Jan 2008

Are these no heat homes?

“We are building homes with no heating systems already.” That was the bold claim made to me by Andy Porter of SIPS@CLAYS at the Harrogate Homebuilding & Renovating show back in November.

“Well, if you are, I’d like to see one,” I replied.

And so it came to pass that on Wednesday of last week, I met up with Andy and he took me to see two of their newly completed homes, one near Beverley in Yorkshire and the other in Accrington, Lancs, both of them what I would call classic selfbuilds.

Both homes had been constructed with Kingspan Tek SIPS panels, 142mm thick, with a U value of 0.2. This is hardly surprising as this is the construction system that SIPS@CLAYS specialise in — they were one of the original Kingspan Tek project partners. One of the houses was double glazed, the other used imported Swedish triple glazing, and both had been fitted with mechanical ventilation with heat recovery (MVHR). Neither house had anything in the way of conventional space heating, but both had wood burning stoves and both had solar thermal panels on the roof.

And what were they like to live in? Had they been cold during our recent cold snaps? Were the residents togged up with woolly hats and scarves, regretting their decision to be so bold as to do away with space heating?

Joan Barker, the builder of the house near Beverley, was still in the process of finishing off the house. She and her husband had moved in about a week before my visit (when it was really cold) and she said that it had been a little chilly for the first two days right after the move, and she admitted to using a couple of 2kW convector heaters to get up to comfort. But since then, no extra heating at all: and the wood burner was only being lit in the evenings. I would have said that she was already one happy bunny, and felt vindicated by her decision to do away with radiators and/or underfloor heating.

In Accrington, David and Jane Hartley had been living in their home since the summer and had had longer to figure out how it was responding. They kept their multifuel Dunsley stove going throughout the winter months (using coal only at night to keep it going) and the MVHR system distributed the heat around the house quite effectively. The room temperatures varied between 14°C and 18°C — not warm by current central heating standards but they found it quite comfortable. Although the stove is located in the middle of the large central living area downstairs, they tended to spend much of their evenings in an upstairs lounge and they noticed that the temperatures were more even upstairs than downstairs, where two of the peripheral rooms were noticeably cooler than the main living area where the stove is. This may be an effect of the uneven distribution of heat via the MVHR ducting.

So have they done it? Are these no heat homes, or are they merely modern variations of houses that might have been built in Beverley and Accrington 100 years ago, heated by solid fuel fires? Are we simply using modern technology (fans and ducting) to shift heat around a house more effectively? These are all interesting questions which I am not sure I can provide a coherent answer to just yet. But in the absence of any genuine Passive Houses in the UK thus far, these SIPs homes stand out as being as close to the new paradigm as we are likely to get in the next few years (being super insulated, pretty airtight, and mechanically ventilated) and they do look to be providing comfortable living conditions with a minimal energy input, which is after all what this low energy thing is all about. I guess the success or failure of these schemes should ultimately be assessed by the size of their fuel bills and in neither instance had they been in occupation long enough to make a judgement on this.

18 Jan 2008

Space heating: where are we headed?

How should we heat our homes? How do we provide comfortable living spaces for people without burning up stupid amounts of energy in so doing?

There is an engineering-type solution to this problem. It’s encapsulated within the Passive House standard. Lots of insulation, triple glazing, air tight like you wouldn’t believe: in short, the house as Thermos Flask. In order to keep the residents alive and healthy, you must have a whole house ventilation system, with added heat recovery so as not to waste a drop of heat. If things turn chilly, you are allowed to fit the odd supplementary heater, either added onto the ventilation systems or something like a wood-burner. By doing all this, you can minimise the space heating energy demand. Really minimise it, although not quite eliminate it. In theory, you can reduce space heating energy requirements so much that they trail in a poor third place behind the other great energy guzzlers, hot water and electrical appliances.

Trouble is that what you have created is akin to being on an aircraft: you live and breathe in a capsule and your comfort is controlled entirely by mechanicals. We know it works because we can survive the worst that Ryan Air can throw at us: besides, people have lived like that in Canada for decades. OK, it makes them a little strange, but survive they certainly do.

The question is would anybody choose to live like this in the UK? And even if they did, would they actually save as much energy as the theory makes out? These are important questions because the way our energy roadmap has been formulated (it’s the Code for Sustainable Homes – again!) we won’t have any choice in the matter. As we live in a relatively mild climate, our traditional response to feeling stuffy is to throw open the window. If people continue to do that, it makes triple glazing look a little bit silly, especially if you are someone who likes to sleep with their windows open a little through the night. Maybe the fact that your house doesn’t have a traditional space heating system will be enough to discourage you from this profligate behaviour, but equally well, you might care about this so little that you go out and buy a bunch of electric convector heaters to keep the temperature up to par.

The thing is that we just don’t know. Mechanical ventilation with heat recovery has to date been fitted mostly into flats with noise issues – where opening windows is a no-no — or by enthusiasts who buy into the idea. Even there, I have visited selfbuilders who have shelled out good money for a system and then don’t use it, often because the fans are themselves a little too noisy. Code Level 6 – what we are all being told we will have to achieve by 2016 — effectively makes whole house ventilation mandatory.

That is quite an experiment. Whilst the theory of mechanical ventilation is well understood, whether it will work in practice and whether people will interact with it in the prescribed manner is still a complete unknown. In Montreal this weekend, the forecast temperature is going to be —14°C: in London it’s +12°C. In Montreal, I would want mechanical ventilation; in London, I am not sure. And yet, as things stand, we are committing ourselves to spending £400million (at £2,000 per pop) every year on it.

Don’t you think it would be a good idea if we were to build and monitor a few thousand airtight homes to see what happens before we roll them out as a national standard? Thus far, we haven't completed one.

15 Jan 2008

Eco Homes, Immigrants and Trains: thought for the day

Interesting to see some of the ideas I have been exploring in this blog over the past year are beginning to receive a wider audience. First an article by John Rentoul in the Independent daring to challenge the idea that building more homes will make housing cheaper.

Then the Sunday Express covers the same story on its front page, but from an immigrant bashing angle. You’ll have to take my word for it because I can’t be bothered to trawl their website for a link. This isn’t essentially an anti-immigrant story, but immigraton does play a part in it because undoubtedly a country with 28 million homes is going to be a more attractive place to move to than one with 25 million, and so 3 million new homes will tend to accelerate the rate of immigration. It’s, if you like, an unintended consequence of a big housebuilding programme.

There is another unintended consequence as well, outlined by Jared Diamond in the New York Times. The carbon footprint of immigrants tends to expand dramatically when they move from a relatively poor country to a relatively rich one, for obvious reasons. Therefore however eco these eco homes may be in their built form, the impact of someone moving into Britain from somewhere less affluent is to increase overall carbon emissions by a wide margin. And that’s without the love miles effect of frequent trips made back to the old country to see the family.

Which brings me onto my final point for the day: the resulting strain on the transport infrastructure caused by new housebuilding. This was brought home to me graphically at the weekend when one of my golf buddies, Steve Gaastra, was describing the hell that is commuting from Cambridge to London by train. The service, for which you pay over £6,000 a year for, is already stretched to breaking point, standing room only at peak times. “It’s no better than a cattle truck: hot, steamy and really unpleasant,” he said. He’s only been doing this commute for a few weeks and already he is looking for a flat to rent in London so he can avoid this twice-daily trauma.

This train service, which is reckoned to be the busiest in Britain, already runs half hourly throughout the day and, because it has to share the East Coast mainline for part of its route, it is already working at full capacity. It is very difficult to see how the carriage congestion could be eased any further, other than charging even more money for a standing place – i.e. rationing by price.

Yet flats around Cambridge station are still being marketed as being “just 45 minutes from Kings Cross.” And of course Cambridge is set to play host to another 25,000 homes over the coming 12 years. All of these new housing estates will be designed with a view to discouraging car use and with the promise of excellent public transport systems being in place as an alternative. But with one of the key links out of the city already full to bursting point, and with little hope of any improvement in sight, the cynical thought crops up that we are just being sold down the river on this one. Just where is everyone going to fit?

14 Jan 2008

Thermal stores: Witherspoon's vision

The thermal store has been knocking around for a long time (at least since the 1980s) and in truth it’s had rather a chequered history. The concept is simple: it’s a hot water battery. You use it like a bank account — in fact, some people prefer the term heat bank to thermal store: you add heat from whatever source you choose, and you withdraw heat from it for your space heating and domestic hot water, indirectly via heat exchangers. As water is capable of storing around five times more heat than concrete or any other solid building material, many designers have got very excited about the possibilities for thermal water storage.

Over the years, the performance of thermal stores has struggled to live up to the hopes, and many of the early examples ended up being energy drains. Space heating and, in particular, domestic hot water require relatively high water temperatures and the fact that the thermal store has to deliver them indirectly, via heat exchange coils, meant that the water in the tank had to reach 80°C in order to deliver an acceptable output and this factor more than cancelled out any potential energy savings.

However, there is one man in Britain who has been busily beavering away on the design of thermal stores for years and he thinks he has overcome most, if not all, the problems relating to thermal stores. That man is Brent Witherspoon, pictured here with one of his prototypes, his company is Chelmer Heating. He has built up a successful business supplying whole house heating systems based around his thermal store designs and he is about to launch another thermal store, known as the EcoCat.

I went to see Brent just before the Xmas break and he spent two hours telling me all about the EcoCat and the thinking behind it. Whereas his existing thermal stores are designed to run on Economy 7 or to be hitched up to an oil or gas fired boiler, the EcoCat is aimed at green power sources, specifically heat pumps, solar panels and wood burners. In particular, Brent sees the EcoCat as a solution to a problem heat pumps have in producing domestic hot water: whilst they work efficiently at raising temperatures through 35°C (enough for underfloor heating), they don’t look so clever when asked to do more work. If you want hot water for the tap at 60°C, then you might just as well use an ordinary electric immersion heater, which is what a lot of heat pump designs do (though they tend to keep rather quiet about it). The Eco Cat is designed to get around this by incorporating an unvented hot water cylinder within it. When the sun shines, the solar panels will supply the bulk of the domestic hot water: and when it doesn’t, there is a small electric boiler to boost the temperature up from what the heat pump can sensibly do.

The EcoCat addresses another problem which Brent has identified: the typical output of a heat pump is 40lts per minute, whereas the typical requirement for an underfloor heating system is less than 20lts per minute and, when some of the circuits are shut down, this can fall to just 5lts per minute. This imbalance results in the return temperature of the water in the underfloor heating system being too high for optimal efficiency, which causes the heat pump to turn on and off far too often and thus perform way below the intended efficiency level. Brent’s design sidesteps the problem by asking the heat pump to heat the water in the EcoCat, rather than feeding directly into the underfloor heating system. It’s an interesting feature and it’s one that thus far Brent is having trouble convincing heat pump manufacturers that they actually need!

But the principle of the EcoCat is to take the proposition of the thermal store and refine it to the point where it really does add value. As you might imagine, it’s quite a complex beast and it sells for over £2,000, way more than any conventional water storage medium you might choose as an alternative. On the other hand, it’s cheaper than virtually all the low carbon and renewable technologies you might think of using in a new house and its purpose is primarily to get them to work together in the most efficient manner possible.

Where Brent sees an economic advantage for his system is that you can build a low carbon heating system around it using an air source heat pump rather than the more expensive ground source version. The fact that air source heat pumps are less efficient than ground source is compensated for by the use of solar thermal.

Brent reckons he can install a heating system for a new house for less than £15,000:
Air source heat pump rated at 17kW - £4,500 (he currently uses the Unico system)
Underfloor heating pipe and controls: £4,000
EcoCat Thermal Store: £2,300
Flat plate solar panels: £3,000
Electric boiler: £900 (this is to get DHW up to temperature in the winter).

So what Brent is essentially offering is a whole house heating and hot water system, based around his unique vision of what the thermal store is capable of. He has identified that it is not enough just to sell a thermal store: to get them to sing, you have to design the whole house heating system around it.

11 Jan 2008

On the Japanese Housing Market

I have long been fascinated in just how differently housebuilding is organised in different countries. And, amongst the world’s wealthy nations, nowhere marks a sharper contrast with the UK than Japan.

This week’s Economist runs a short piece about trends in the Japanese housing market. It starts with the counter-intuitive point that whilst the building codes now demand that new homes should be capable of surviving earthquakes, their typical lifespan is no more than 30 years. More than 60% of Japan’s homes have been built since 1980 and only 5% of the ones still standing were built before 1950.

The roots of this enormous turnover in housing may in fact be to do with earthquakes. The Japanese are used to having their homes wrecked every now and then by forces beyond their control, and so they have traditionally valued the land on which the homes sit, rather than the homes themselves. This is reflected in the legal system that separates the land from the buildings.

Whilst some of us marvel at the ability of the Japanese to re-invent their housing stock every generation, the Japanese themselves are worried by their profligacy and think it may be time to start building more durable structures. The Prime Minister, Yasuo Fukuda, is about to introduce new rules to encourage “200 year homes”, with tax breaks for houses that adhere to more robust building standards. But this is probably only a beginning of a lengthy process. Japan has no culture of buying old homes, no surveyors capable of assessing them, no mortgage lenders prepared to take risks on old homes, and no construction businesses that can maintain and repair them.

On the other hand, they have the capability of replacing their housing stock within a generation. If they introduced something like the Code for Sustainable Homes as part of their more robust details, they could make a huge impact on their national energy consumption and in a timescale that might have some meaningful effect on climate change.

In contrast, we replace so little housing in this country (under 0.1% per annum, as opposed to 3% in Japan), that our efforts thus far to green our new housing standards are destined to have negligible impact on our overall carbon emissions.

3 Jan 2008

HIPS update

Whilst the housing market may be taking a bath, many people (OK… Kirstie Allsports) are tempted to blame the introduction of HIPS which are now required on all new homes in England & Wales. But the price of providing these seems to be falling by the day. There are now apparently 10,000 trained Energy Assessors and they are getting as little as £60 a house for their efforts. Methinks they’d be better off with a window cleaning round. Many estate agents are swallowing the extra costs within their fee structures in any event.

Compared with the huge increases in stamp duty on property purchases, brought in by Chancellor Gordon Brown in his first budget in 1997, the cost of HIPs is nothing but a minor irritant.

2 Jan 2008

2008 — The Cambridge Agenda

Interesting article in the Cambridge Evening News today summarising what lies ahead for the city over the coming years. Bear in mind, this is a city with a population of around 120,000, consisting of around 50,000 homes.

• Cambridge East — the Marshall’s airport site — is expected to become the location for 10,000 new homes. The downside is that a major local employer (Marshalls) is going to have to be relocated 20 or 30 miles away, which will involve hundreds of thousands of extra journeys every year.

• Southern Fringe — 3,000 homes to be built near the hospital.

• North West Fringe — 1,800 homes next to the A14, plus more student accommodation.

• Central Cambridge — the station site is due to be re-resubmitted to the planners shortly. Not sure how many homes, but it’s basically hundreds, if not thousands, of flats.

• Northstowe — a new town of 9,500 homes, six miles north of the centre of Cambridge, located on the guided bus route. It is going through public consultation at the moment.

Correct me if I am wrong, but that’s around 25,000 new homes in the pipeline. When that’s all done and dusted, Cambridge will be 50% bigger than it is already. And it’s already squashed and overcrowded.

And what are they doing in terms of infrastructure to support all these new citizens? The railways are already running at full capacity. There’s not an awful lot they can do about this. There are no plans to upgrade the M11 to London. The A14, which is already dangerous, is being upgraded from four lanes to six, but it’s going to take about five years of roadworks to do it and, even then, it will only be the correct size for what we have now, not what we’ll have by the time all these new homes are finished.

Not forgetting the £100million guided bus route which will connect Northstowe with the city and the hospital, but which is actually a complete punt in the dark: no one has ever built one in Britain before and we have no idea whether it will work as planned. Even if it does work well, it’s only going to take a small part of the additional transport load.

On the demand reduction side, we have a proposal for a congestion charge that will operate around the city for two hours every weekday morning. Hmm.

Personally, I don’t get it. I know Cambridge is regarded as a successful town, and a good place to live, but how can increasing its size like this be regarded as sustainable? The expansion is being partly sold to us as a way to provide affordable housing, but if Milton Keynes is anything to go by, the new building programme won’t make any difference to house prices at all, because people are prepared to travel from near and far to live near Cambridge. They will.

By 2020, Cambridge will be a lot bigger, far busier, and no cheaper to live in than it would have been had we left it alone. In what way is this an improvement?