Regular readers will be aware of Prof David Mackay and his book Sustainability Without the Hot Air, which was published to rave reviews at 2008. It's also available free online as a pdf.
In it, he runs through the numbers needed to get the UK off fossil fuel and in one chapter (27) he outlines five different plans which would enable us to do this. Now, David is very careful not to stick his neck out on a limb here and say which one he thinks is best, but it's hard not to conclude that his money is on Plan E, the nuclear option. He has already given nuclear a big thumbs up (in Ch 24) and in Ch 27 he prefaces Plan E by stating:
E stands for “economics.” This fifth plan is a rough guess for what might
happen in a liberated energy market with a strong carbon price. On a level
economic playing field with a strong price signal preventing the emission
of CO2, we don’t expect a diverse solution with a wide range of power-
costs; rather, we expect an economically optimal solution that delivers the
required power at the lowest cost. And when “clean coal” and nuclear go
head to head on price, it’s nuclear that wins.
In other words, the nuclear option is safe, clean and the cheapest option of the five presented. What's not to like? If Apple produced an iNuke, we'd be lapping them up. But Apple don't do nukes, and there is a certain amount of consumer resistance here, especially in Germany and Japan.
Fast forward three years and David Mackay finds himself the Chief Scientist at the Department for Energy and Climate Change, in charge of a project called the 2050 Pathways Calculator which is used to inform the government's Carbon Plan for the years between now and 2050 when (the plan is) to reduce our CO2 emissions by 80%.
Now the 2050 Pathways Calculator is based on a vast Excel spreadsheet and consequently it's very difficult to comprehend, especially as its populated by so much interactive data. But at heart its mission remains very similar to what was set out in Ch 27 of David's book - namely to come up with some plans or pathways to get the UK off fossil fuels by 2050.
The front-end of the calculator (i.e. the bit we see) is not that difficult to comprehend. The choices are split into two parts: firstly, how to decrease demand (for all energy) and, secondly, how to increase supply of low-carbon energy. We are invited to take control and see how we would pilot the mothership.
Twiddling the controls, it quickly becomes apparent that we can't do this by demand reduction alone. Our legacy infrastructure is so wasteful of energy that it's inconceivable that we can bring about an 80% reduction in the amount of energy we consume in the UK, especially as these models take for granted that we still have economic growth at around 2% per annum and a rising population.
After much gnashing of teeth, it becomes apparent that about the best thing we can do on the demand side is to switch everything as we can think of over to electricity. So houses should switch to heat pumps, cars to batteries and industrial processes to anything but fossil fuels. Insulation and behaviour change help a bit, but they are basically second order effects — insignificant in the great scheme of things.
Which leads us onto part 2 of the calculation, the supply side, or how the hell are we going to create all this low carbon electricity. The calculator permits you to choose four options for each technology. In each case Option 1 is basically do nothing and Option 4 is the Max Out button. You can jiggle and you can jaggle and you can find dozens of ways of producing enough juice to get the overall CO2 emissions down by 80%, provided you have done some demand reduction and you add it a little biofuel. There is something for everyone here and the green pressure groups are delighted because it shows (once and for all) that we can get there without a drop of nuclear energy, which is now the German option.
But of course, we are still faced with the economic logic of David Mackay's Plan E. Surely, when all is said and done, Plan E, the nuclear option will be the cheapest?
Well you wouldn't know it to behold the latest version of the 2050 Calculator which now has costs attached to it. It's still in beta, but it's available online, complete with some sample pathways to check out. The closest option to Plan E is the one labelled Higher Nuclear, Less Energy Efficiency, although why these two should be paired isn't explained. The point is that's it's not the cheapest option and even if you tweak it so it's higher nuclear plus lots of energy efficiency, it's still more expensive than the best in class, which is known as Markal 3.26 (don't ask!).
Markal 3.26 is as bit of a mish-mash, using a bit of everything including carbon capture and storage, lots of wind, some waves, some biofuel, and a bit of nuclear. In other words, almost exactly what David himself had warned us wouldn't be the cheapest option when he introduced Plan E in his book (see the quote in italics above). History tells us that when there is a race to develop competing technologies to carry out the same task, then pretty quickly one wins out. But the 2050 Calculator is sitting on the fence, not picking a winner or even indicating what the cheapest option might be.
Now buried deep inside this version of the Calculator is a wiki which lists all of the cost assumptions used to make the latest version. The project boasts of being open source and anyone can come along and edit the wiki, which sounds like a great idea. Except that hardly anyone has bothered (few seem to know of its existence) so that around 98% of the entries are from the DECC staff members charged with populating the calculator with data.
Dig around the wiki and you'll find an interesting item called the Worry List and on the list is an interesting item called Are We Going To Try And Answer The Really Big Questions:
• What is the cheapest pathway?
• Is it cheaper / how much more expensive is it to tackle climate change than to not?
• What are the biggest costs in tackling climate change?
• What are the biggest sources of uncertainty in tackling climate change?
• Is it cheaper to be more energy efficient or to build more capacity?
• Is nuclear cheaper than wind or CCS?
In theory, the costed version of the Calculator should answer all these questions but in practice the various pathways turn out to be very similar cost-wise, even the cost of doing nothing at all about climate mitigation. Which has surprised some right-wing commentators (cf Worstall, Booker). And it also surprised me. I was expecting a clear winner, not a photo-finish.
It's at this point that I begin to suspect that politics may be overriding arithmetic, and that the 2050 calculator has been tweaked to give the answers that the government wants to hear — i.e. that it's on the right track, and that what it proposes in its Carbon Plan is the best way forward. Far from challenging conventional wisdom on sustainable energy, the Calculator results seem to re-infoce it.
I wonder what David Mackay thinks? Has his baby been hijacked by political expediency? Or were his original back-of-the-envelope style calculations simply wrong? Because what has emerged from the 2050 calculator exercise looks very different to what he set out in Chapter 27 of his book.
10 Jan 2012
HS2: bonkers?
I've just been listening to Transport Minister Justine Greening announcing the go-ahead for HS2, the high speed line to connect London with Brum, Manchester and Leeds. She's sounded so upbeat, so full of promise. But every time I hear about this project, my own heart sinks. There have been hundreds of thousands of words expended on this subject already, mostly by people with a far better grasp on rail travel than me, but I feel like unloading my take on it. That's what a blog is for, isn't it?
Firstly the amount, widely reported as being around £33b, roughly three times the cost of the Olympics (don't get me started on that). Except there don't appear to be any sponsors or private investment. If it's that good a deal, why aren't private investors coming forward, like they did when the Victorians first put railways in place? Why is the government suddenly acting like a Soviet republic? Could it be that no one much cares about the few minutes shaved off journey times? No one wants the higher fares this will involve, and no business is daft enough to stump up?
And compare this to how stingy the government have been over Feed In Tariffs. As you may well have sussed by now, I'm no fan of FiTs, but the total subsidy is still small beer compared to HS2. Not to mention the fact that the government wasn't actually paying for FiTs - it is coming from everyones' electricity bills.
If the government were to replicate the same way of producing funds for HS2 as they have for FiTs, then the £33b could be spread amongst the 1.35billion passenger rail journeys made each year. If you added £1 to all of these journeys for the next 25 years, that would pay for HS2. Of course, only those travelling along the HS2 would benefit, but that's pretty much how FiTs are designed to work, so why not?
I'll tell you. Because the outcry would be so great that every right wing paper would have a fit of a very different variety — think stealth tax — and the plan would be dropped before you could say Justine Greening.
So no, instead the money is coming from the CapEx section of general expenditure, no doubt spread out over 50 years to make it look small. But it's a bollockingly large amount of money. It's £500 each. How many of us would elect to pay £500 for HS2 to be built? Now we have no choice.
What really browns me off is the point that I hear Christian Wolmar often making. That the rail network could badly do with a make-over and this £33b won't get spent on it because it's all going on HS2. To get from my home town, Cambridge, to Manchester by train takes 4hours. From London, 50 miles further away, Manchester is just 2hrs 10min, with a service running every 20 minutes.
Birmingham is worse still. 2 hours 40 mins from Cambridge by train — a distance of just 97 miles. In contrast, London is 118 miles distant but the journey takes just 1hr 25m. OK, Cambridge is a small town, but you could just as well substitute Bristol, Southampton, Cardiff, Swindon, Derby, you name it: the trains to them will all go at half speed or less than the London connections.
Our trains services always have been very London-centric and it seems absurd to me to be making them even more so. If we really want to get more people out of their cars and into a train, then how about improving cross country services?
Firstly the amount, widely reported as being around £33b, roughly three times the cost of the Olympics (don't get me started on that). Except there don't appear to be any sponsors or private investment. If it's that good a deal, why aren't private investors coming forward, like they did when the Victorians first put railways in place? Why is the government suddenly acting like a Soviet republic? Could it be that no one much cares about the few minutes shaved off journey times? No one wants the higher fares this will involve, and no business is daft enough to stump up?
And compare this to how stingy the government have been over Feed In Tariffs. As you may well have sussed by now, I'm no fan of FiTs, but the total subsidy is still small beer compared to HS2. Not to mention the fact that the government wasn't actually paying for FiTs - it is coming from everyones' electricity bills.
If the government were to replicate the same way of producing funds for HS2 as they have for FiTs, then the £33b could be spread amongst the 1.35billion passenger rail journeys made each year. If you added £1 to all of these journeys for the next 25 years, that would pay for HS2. Of course, only those travelling along the HS2 would benefit, but that's pretty much how FiTs are designed to work, so why not?
I'll tell you. Because the outcry would be so great that every right wing paper would have a fit of a very different variety — think stealth tax — and the plan would be dropped before you could say Justine Greening.
So no, instead the money is coming from the CapEx section of general expenditure, no doubt spread out over 50 years to make it look small. But it's a bollockingly large amount of money. It's £500 each. How many of us would elect to pay £500 for HS2 to be built? Now we have no choice.
What really browns me off is the point that I hear Christian Wolmar often making. That the rail network could badly do with a make-over and this £33b won't get spent on it because it's all going on HS2. To get from my home town, Cambridge, to Manchester by train takes 4hours. From London, 50 miles further away, Manchester is just 2hrs 10min, with a service running every 20 minutes.
Birmingham is worse still. 2 hours 40 mins from Cambridge by train — a distance of just 97 miles. In contrast, London is 118 miles distant but the journey takes just 1hr 25m. OK, Cambridge is a small town, but you could just as well substitute Bristol, Southampton, Cardiff, Swindon, Derby, you name it: the trains to them will all go at half speed or less than the London connections.
Our trains services always have been very London-centric and it seems absurd to me to be making them even more so. If we really want to get more people out of their cars and into a train, then how about improving cross country services?
9 Jan 2012
The God Species
Mark Lynas has a not-so-new book out, the God Species, and I've been taking post-Xmas read. Lynas is now identified as one of the leaders of the new wave of techno-greens who have turned their backs on traditional environmental thinking and embraced science and technology as the way forward. Bring on more nukes, lots of them please, and don't get hung up about GM foods or, for that matter, over-population. It's both refreshing and thought provoking and I look forward to reading more.
The basic premise of the book is that there are a number of planetary boundaries which we cross at our peril. Lynas identifies nine of them and devotes a chapter to each. Now this concept is a variation (a significant one) on the One Planet theme developed by WWF and others, and the original Limits to Growth style thinking dating back to the 1970s.
Each chapter follows a pattern. Lynas starts by describing the science surrounding the boundary and then moves on to reflect on how we should best deal with the problem. Thus the work is part pop-science, part polemic, and the book as a whole develops a roller coaster feel to it: we chug slowly uphill as we work through the facts and then let go for a breath-taking ride as we consider what the hell we should do about it. Generally, the polemic side is much the easier read, especially when it comes to refuting his previously held (green) convictions. This mea culpa aspect lends the book something of a confessional feel which makes it highly personal and consequently very accessible, something of a triumph for this subject, which despite its importance has been seen as just a little nerdy and very male - just why are there so few women writing about climate change and planetary boundaries?
So is Mark Lynas right? Is his position midway between traditional greenery (anti nukes, anti capitalism, anti progress) and gung-ho economic conservatism ("it's all an excuse to raise taxes so bugger off and leave us alone") the answer? He has my vote and there are an increasing number of influential commentators who line up in this camp, notably George Monbiot and Stuart Brand, not to mention a large number of scientists who traditionally steer clear of policy and are therefore reluctant to put their heads above the parapet.
But whether we like it or not, the debate has become highly politicised and just because Lynas is talking sense doesn't make the way forward any easier. For me, the most interesting chapter is the one dealing with the ozone layer - planetary boundary No 9 - and the way we appear to have solved the problem. It turns out the 1986 Montral Protocol, which addressed CFC production worldwide, was not the shoe-in I'd imagined it to be and that it took an enormous amount of cajoling and political manoeuvring to get it in place. The businesses which stood to take a pasting - principally American - dragged their heels and applied spoiling tactics and the Europeans were particularly obstructive. The key to its success was American political involvement and yet this all took place during the Reagan years. America simply threatened everyone with a big stick if they didn't comply and the rest of the world meekly fell into place. And within a few years, the world has learned to cope without CFCs and the ozone layer was on the road to recovery.
It all makes for a painful contrast with the Kyoto Protocol which was negotiated ten years later. Here the Americans, despite being led by Clinton and Gore, played a wrecking game and refused to sign up to anything meaningful. Climate change negotiations have never recovered from this setback. As a trusted advisor to the president of the Maldives, Lynas had a ringside seat at the Copenhagen summit and describes graphically what happened in the final hours of negotiation - all rather depressing.
But Lynas points out that our planetary problems are all solvable and that technically it is not even that difficult. We don't have to return to the dark ages and we don't have to restrict ourselves to a one child policy. We can house, feed and heat 9 million on this planet if only we can agree a few basic house rules. We don't even have to abandon economic growth, as long as we don't transgress a number of scientifically defined boundaries. We are, as the title implies, in a position to manage the planet, but right now we seem to lack the resolve to do so.
Thus it's both an uplifting read, in that it points a direct route out of the morass we've created, but a sobering one as well in that it draws a blank on how exactly we might get there politically.
The basic premise of the book is that there are a number of planetary boundaries which we cross at our peril. Lynas identifies nine of them and devotes a chapter to each. Now this concept is a variation (a significant one) on the One Planet theme developed by WWF and others, and the original Limits to Growth style thinking dating back to the 1970s.
Each chapter follows a pattern. Lynas starts by describing the science surrounding the boundary and then moves on to reflect on how we should best deal with the problem. Thus the work is part pop-science, part polemic, and the book as a whole develops a roller coaster feel to it: we chug slowly uphill as we work through the facts and then let go for a breath-taking ride as we consider what the hell we should do about it. Generally, the polemic side is much the easier read, especially when it comes to refuting his previously held (green) convictions. This mea culpa aspect lends the book something of a confessional feel which makes it highly personal and consequently very accessible, something of a triumph for this subject, which despite its importance has been seen as just a little nerdy and very male - just why are there so few women writing about climate change and planetary boundaries?
So is Mark Lynas right? Is his position midway between traditional greenery (anti nukes, anti capitalism, anti progress) and gung-ho economic conservatism ("it's all an excuse to raise taxes so bugger off and leave us alone") the answer? He has my vote and there are an increasing number of influential commentators who line up in this camp, notably George Monbiot and Stuart Brand, not to mention a large number of scientists who traditionally steer clear of policy and are therefore reluctant to put their heads above the parapet.
But whether we like it or not, the debate has become highly politicised and just because Lynas is talking sense doesn't make the way forward any easier. For me, the most interesting chapter is the one dealing with the ozone layer - planetary boundary No 9 - and the way we appear to have solved the problem. It turns out the 1986 Montral Protocol, which addressed CFC production worldwide, was not the shoe-in I'd imagined it to be and that it took an enormous amount of cajoling and political manoeuvring to get it in place. The businesses which stood to take a pasting - principally American - dragged their heels and applied spoiling tactics and the Europeans were particularly obstructive. The key to its success was American political involvement and yet this all took place during the Reagan years. America simply threatened everyone with a big stick if they didn't comply and the rest of the world meekly fell into place. And within a few years, the world has learned to cope without CFCs and the ozone layer was on the road to recovery.
It all makes for a painful contrast with the Kyoto Protocol which was negotiated ten years later. Here the Americans, despite being led by Clinton and Gore, played a wrecking game and refused to sign up to anything meaningful. Climate change negotiations have never recovered from this setback. As a trusted advisor to the president of the Maldives, Lynas had a ringside seat at the Copenhagen summit and describes graphically what happened in the final hours of negotiation - all rather depressing.
But Lynas points out that our planetary problems are all solvable and that technically it is not even that difficult. We don't have to return to the dark ages and we don't have to restrict ourselves to a one child policy. We can house, feed and heat 9 million on this planet if only we can agree a few basic house rules. We don't even have to abandon economic growth, as long as we don't transgress a number of scientifically defined boundaries. We are, as the title implies, in a position to manage the planet, but right now we seem to lack the resolve to do so.
Thus it's both an uplifting read, in that it points a direct route out of the morass we've created, but a sobering one as well in that it draws a blank on how exactly we might get there politically.
15 Dec 2011
How accurate are QSs?
Mark,
I have a number of editions of your book and am now on the brink of my first self build. We have planning permission and detailed designs, and have had a couple of builders tender for the work, which was a condition from the bank in order that they would fund the project. However the costs are more expensive than I planned (surprise surprise I hear you say), and when I costed some of the major elements (ground works, external walls, roof) using your latest book, I came to half the price quoted by the builders. I have also got a few local sub contractors to quote and their numbers match mine not the builders
So I have employed a quantity surveyor to do it properly on my behalf, and am now the proud owner of 25 pages of costs for the project. Thankfully I am comfortable with this kind of numerical analysis, but I cam imagine at this stage most peoples eyes glaze over ! Unfortunately his numbers come in very similar to the builders (They would do wouldn't they I hear you say, they have both used QSs to cost the project and QSs will generally use the same process and hence come up with the same cost).
My analysis of some of the big numbers suggests that some of my QS's numbers are the same as the numbers from your book, but some are significantly more expensive (50% to 100%) more.
So my question is as a self builder what would your guidance be regarding the cost you can self build for Vs a cost given by a QS. Is there always fat in the QS figure to cover eventualities ? I guess I'm hoping for a shortcut rather than go through and cost the whole project using your book to come up with the relevant figure.
I want to self build but want to be ensure that there is a saving in there by doing this.
Regards,
John
John,
Good to hear from you.
My feeling is that you are coming up against one of the age-old conundrums in building in that an awful lot of pricing is an art rather than a science. An expensive QS is probably about as accurate as you can get, but if you were to ask three other expensive QSs to undertake the same task you would get three different results. And so it is with builders quotes. They will assess the size and difficulties of each task slightly differently and, crucially, they will assess the risk of these tasks being completed on time and on budget quite differently. The more off-beat the project, the more widely varied the quotations will be. My cost tables are really only there to provide the roughest of guidelines, not to construct quotations.
One of the critical factors is risk - or more accurately the perception of risk. You have referred to it as fat which is how many people think of it. but its really a risk premium paid by you for them taking on the fixed price quotation. IE the risk of cost overrun is being transferred from you to them, and this is, if you like, insurance money for them taking on this risk. In theory, you can do away with this risk premium by becoming your own contractor/project manager, but you will only save money if everything (OK, most things) goes according to plan. If you prove to be a lousy or an unlucky manager, you may end up spending more money than the fattest of fat builder's quote.
I hope this helps. I realise this is very general advice, but as you note, it's a common problem which people undertaking selfbuilds face. We all want it to be costed out simply like a shopping list, but it almost invariably never works out like that.
Mark
Mark,
Thanks for your response. I think you maybe underestimating the value of your cost tables ! In your book you actually break each of the tasks down into material and labour which makes it easy to add up the totals. However the QS uses a fixed rate for tasks which includes labour, materials and equipment (i.e. £24 per sqm of blockwork - which I think is spot on for blockwork but some of the others seem very high). This makes it very hard to break down to see what is actually costed without working out the materials. Indeed the QS bemoaned the fact that in the old days he use to produce a bill of materials but now no one wants it. They just use the fixed rate to work out the costs, and then only ever plan one stage ahead. However he is very reluctant to produce a bill of materials for me.
I've just re-read your chapter on project management and it all rings true. I would just love to have the complete bill of materials so I could see once and for all how much the materials would cost Vs labour. If I use the QS's 40% is material and 60% is labour, then if I assume each subbie earns £200 per day (quite generous ?) then the labour cost is the equivalent of 10 people for a whole year !
Regards
John
John,
Thanks for the interesting feedback. I spend a ridiculous amount of time on these cost tables and rarely get any feedback on how people use them.
Mark
I have a number of editions of your book and am now on the brink of my first self build. We have planning permission and detailed designs, and have had a couple of builders tender for the work, which was a condition from the bank in order that they would fund the project. However the costs are more expensive than I planned (surprise surprise I hear you say), and when I costed some of the major elements (ground works, external walls, roof) using your latest book, I came to half the price quoted by the builders. I have also got a few local sub contractors to quote and their numbers match mine not the builders
So I have employed a quantity surveyor to do it properly on my behalf, and am now the proud owner of 25 pages of costs for the project. Thankfully I am comfortable with this kind of numerical analysis, but I cam imagine at this stage most peoples eyes glaze over ! Unfortunately his numbers come in very similar to the builders (They would do wouldn't they I hear you say, they have both used QSs to cost the project and QSs will generally use the same process and hence come up with the same cost).
My analysis of some of the big numbers suggests that some of my QS's numbers are the same as the numbers from your book, but some are significantly more expensive (50% to 100%) more.
So my question is as a self builder what would your guidance be regarding the cost you can self build for Vs a cost given by a QS. Is there always fat in the QS figure to cover eventualities ? I guess I'm hoping for a shortcut rather than go through and cost the whole project using your book to come up with the relevant figure.
I want to self build but want to be ensure that there is a saving in there by doing this.
Regards,
John
John,
Good to hear from you.
My feeling is that you are coming up against one of the age-old conundrums in building in that an awful lot of pricing is an art rather than a science. An expensive QS is probably about as accurate as you can get, but if you were to ask three other expensive QSs to undertake the same task you would get three different results. And so it is with builders quotes. They will assess the size and difficulties of each task slightly differently and, crucially, they will assess the risk of these tasks being completed on time and on budget quite differently. The more off-beat the project, the more widely varied the quotations will be. My cost tables are really only there to provide the roughest of guidelines, not to construct quotations.
One of the critical factors is risk - or more accurately the perception of risk. You have referred to it as fat which is how many people think of it. but its really a risk premium paid by you for them taking on the fixed price quotation. IE the risk of cost overrun is being transferred from you to them, and this is, if you like, insurance money for them taking on this risk. In theory, you can do away with this risk premium by becoming your own contractor/project manager, but you will only save money if everything (OK, most things) goes according to plan. If you prove to be a lousy or an unlucky manager, you may end up spending more money than the fattest of fat builder's quote.
I hope this helps. I realise this is very general advice, but as you note, it's a common problem which people undertaking selfbuilds face. We all want it to be costed out simply like a shopping list, but it almost invariably never works out like that.
Mark
Mark,
Thanks for your response. I think you maybe underestimating the value of your cost tables ! In your book you actually break each of the tasks down into material and labour which makes it easy to add up the totals. However the QS uses a fixed rate for tasks which includes labour, materials and equipment (i.e. £24 per sqm of blockwork - which I think is spot on for blockwork but some of the others seem very high). This makes it very hard to break down to see what is actually costed without working out the materials. Indeed the QS bemoaned the fact that in the old days he use to produce a bill of materials but now no one wants it. They just use the fixed rate to work out the costs, and then only ever plan one stage ahead. However he is very reluctant to produce a bill of materials for me.
I've just re-read your chapter on project management and it all rings true. I would just love to have the complete bill of materials so I could see once and for all how much the materials would cost Vs labour. If I use the QS's 40% is material and 60% is labour, then if I assume each subbie earns £200 per day (quite generous ?) then the labour cost is the equivalent of 10 people for a whole year !
Regards
John
John,
Thanks for the interesting feedback. I spend a ridiculous amount of time on these cost tables and rarely get any feedback on how people use them.
Mark
9 Dec 2011
Are empty homes really a scandal?
This week we've been treated to a new housing campaign, launched on Channel 4. The problem — no, let's get this in perspective — the scandal of empty homes. George Clarke has been bestriding our screens examining what has been going down. From the bits I've seen, he has mostly been laying into the now discredited Pathfinder Policy of the last government, which sought to rip up old terraced streets up North and replace them with state-of-the-art, zero-carbon flats, or Yvettes, as they never quite came to be known.
You can trawl up and down Liverpool, Stoke-on-Trent or Sunderland and find really depressing looking wastelands of derelict and boarded-up housing estates. As Clarke kept pointing out, these could all be done up for.....well, it wasn't entirely clear how much. The key fact that he kept reiterating was that it was cheaper to do them up than it was to build new.
But the research from the Technology Strategy Board's Retrofit for the Future programme suggests otherwise. That is that if you are to create good homes fit for 2050 and our low carbon future, rebuilding may well be a more sensible and cheaper option.
Bringing these homes back to life would be expensive, however you go about it. And the fact is there may well be very little demand for these renovated or rebuilt homes in the private market. Liverpool, Stoke-on-Trent, Sunderland — none of them are exactly setting the jobs market alight at the moment. Set against the demand for affordable homes in these towns, things look very different, but that's not a market demand which would lead to people come in and spend money on these houses in return for sensible financial return.
So juxtaposing the number of empty homes with the affordable housing demand may look compelling, but it's voodoo economics. The fact is there isn't enough money for affordable homes whether it's building new ones or doing up empty ones.
Which isn't to say that there must be some spots where terraces of empty homes could be given over to enthusiastic community selfbuilders to make of them what they will. David Ireland makes this point in his open letter.
But the truth is that there will still be one hell of a lot of empty homes in places where no one is ever going to find a sensible use for them. It's very sad, but I'm not sure it really counts as a scandal.
You can trawl up and down Liverpool, Stoke-on-Trent or Sunderland and find really depressing looking wastelands of derelict and boarded-up housing estates. As Clarke kept pointing out, these could all be done up for.....well, it wasn't entirely clear how much. The key fact that he kept reiterating was that it was cheaper to do them up than it was to build new.
But the research from the Technology Strategy Board's Retrofit for the Future programme suggests otherwise. That is that if you are to create good homes fit for 2050 and our low carbon future, rebuilding may well be a more sensible and cheaper option.
Bringing these homes back to life would be expensive, however you go about it. And the fact is there may well be very little demand for these renovated or rebuilt homes in the private market. Liverpool, Stoke-on-Trent, Sunderland — none of them are exactly setting the jobs market alight at the moment. Set against the demand for affordable homes in these towns, things look very different, but that's not a market demand which would lead to people come in and spend money on these houses in return for sensible financial return.
So juxtaposing the number of empty homes with the affordable housing demand may look compelling, but it's voodoo economics. The fact is there isn't enough money for affordable homes whether it's building new ones or doing up empty ones.
Which isn't to say that there must be some spots where terraces of empty homes could be given over to enthusiastic community selfbuilders to make of them what they will. David Ireland makes this point in his open letter.
But the truth is that there will still be one hell of a lot of empty homes in places where no one is ever going to find a sensible use for them. It's very sad, but I'm not sure it really counts as a scandal.
14 Nov 2011
Does Passiv mean Massive?
Ken Neal makes some interesting points on my last but one post.
• I do prefer to design passive houses rather than a PassivHaus, which are really active houses with all the kit and controls required. I do use and agree with all the standards, especially the airtightness but prefer to use passive stack ventilation. The additional heating load is about 1kW on a reasonably sized house which can be met, in rural areas where most of my designs are, by using a small wood stove.
Is he right? I don't think so. The Passivhaus only really requires one bit of kit - the mechanical ventilation system (MVHR). Sure, this kit requires controls, but they are not overly complex. Think Off — On — Boost. That's pretty much it, although there may be some element of timing involved as well. But nothing more complicated than a conventional heating system. And if you do choose to use natural ventilation instead of MVHR, you have the problem of not being able to circulate the warm air around the house, so that your wood stove wouldn't be heating the other rooms in the house. Natural ventilation requires significant input on the air intake side and that can realistically only mean trickle vents, which immediately blows a hole in your airtightness strategy. You can see why Passivhaus and natural ventilation don't really go hand in hand.
• I also prefer thermally massive houses, where you can get several days carry over of heat, to typical PassivHaus lightweight structures.
Passivhaus is agnostic on this point. There is no presumption in favour of lightweight or heavyweight structures. You can have whatever you want, so long as the thermal sums add up.
• I like a house which just sits there and does its thing on its own with very little control or active input.
Well, that is pretty much what a Passivhaus is aiming to do. But to get there, you need MVHR. Natural ventilation just doesn't cut it.
• Regarding embodied energy in materials, this only becomes significant if you are designing for a short life, say sixty years. In our energy constrained future we won't be able to build quantities of new houses, or alter significantly existing ones, because the energy to do so will be in short supply or too expensive or both. If you look at the age of some of our present housing there is no reason to suppose that a well built passive house won't last for three or four hundred years. So over that lifespan embodies energy is a very small proportion of the energy used in a building.
Basically, I agree with Ken on this point. But it does rather contradict his first point about the additional 1kW heating load placed upon a house without MVHR. Because that 1kW load will mount up over the lifetime of a house. After about twenty years, it will equate to the embodied energy of a lightweight house. After 40 or 50 years it will equal that of a heavy, masonry house. Those kilowatts, they all add up.
Mike Jones also makes some interesting comments on the same post.
• I plan to self-build to Passivhaus standard but I'd like a simple efficient MHRV system that I can service myself so I do not have expensive maintenance costs. Are the Passivhaus recommended MHRV systems easy to maintain by the householder or is maintenance a factor to be added to the building running costs? Anyone know?
I don't know enough about MVHR to answer that for sure. One of the issues to be resolved is that whilst there are dozens of MVHR systems on the market, very few are "Passivhaus certified." And whether these need professional servicing, I have no idea.
• I do prefer to design passive houses rather than a PassivHaus, which are really active houses with all the kit and controls required. I do use and agree with all the standards, especially the airtightness but prefer to use passive stack ventilation. The additional heating load is about 1kW on a reasonably sized house which can be met, in rural areas where most of my designs are, by using a small wood stove.
Is he right? I don't think so. The Passivhaus only really requires one bit of kit - the mechanical ventilation system (MVHR). Sure, this kit requires controls, but they are not overly complex. Think Off — On — Boost. That's pretty much it, although there may be some element of timing involved as well. But nothing more complicated than a conventional heating system. And if you do choose to use natural ventilation instead of MVHR, you have the problem of not being able to circulate the warm air around the house, so that your wood stove wouldn't be heating the other rooms in the house. Natural ventilation requires significant input on the air intake side and that can realistically only mean trickle vents, which immediately blows a hole in your airtightness strategy. You can see why Passivhaus and natural ventilation don't really go hand in hand.
• I also prefer thermally massive houses, where you can get several days carry over of heat, to typical PassivHaus lightweight structures.
Passivhaus is agnostic on this point. There is no presumption in favour of lightweight or heavyweight structures. You can have whatever you want, so long as the thermal sums add up.
• I like a house which just sits there and does its thing on its own with very little control or active input.
Well, that is pretty much what a Passivhaus is aiming to do. But to get there, you need MVHR. Natural ventilation just doesn't cut it.
• Regarding embodied energy in materials, this only becomes significant if you are designing for a short life, say sixty years. In our energy constrained future we won't be able to build quantities of new houses, or alter significantly existing ones, because the energy to do so will be in short supply or too expensive or both. If you look at the age of some of our present housing there is no reason to suppose that a well built passive house won't last for three or four hundred years. So over that lifespan embodies energy is a very small proportion of the energy used in a building.
Basically, I agree with Ken on this point. But it does rather contradict his first point about the additional 1kW heating load placed upon a house without MVHR. Because that 1kW load will mount up over the lifetime of a house. After about twenty years, it will equate to the embodied energy of a lightweight house. After 40 or 50 years it will equal that of a heavy, masonry house. Those kilowatts, they all add up.
Mike Jones also makes some interesting comments on the same post.
• I plan to self-build to Passivhaus standard but I'd like a simple efficient MHRV system that I can service myself so I do not have expensive maintenance costs. Are the Passivhaus recommended MHRV systems easy to maintain by the householder or is maintenance a factor to be added to the building running costs? Anyone know?
I don't know enough about MVHR to answer that for sure. One of the issues to be resolved is that whilst there are dozens of MVHR systems on the market, very few are "Passivhaus certified." And whether these need professional servicing, I have no idea.
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