I was posed this question by a guy from Essex at last weekend’s Homebuilding & Renovating show in London. I said I had an idea that it was something like a bungalow with a loft conversion, although on reflection it seems strange to count a loft conversion as half a storey. So in turn I asked him why he wanted to know.
Turns out, of course, that he was in dispute with the planners over just what he could and couldn’t build in his garden. He’d won planning permission, at appeal, for a one-and-a-half storey house and had subsequently drawn up plans for a house where the eaves lines intersects with the bottom of the upper floor windows, in effect turning them into dormers. It’s a common enough design, a sort of English country cottage look. But was it one-and-a-half storeys or two?
Guess what the planners thought? They are insisting that he redraw his plans with the eaves line about 1500mm lower so that it was immediately above the top of the ground floor windows. That, to them, was a one-and-a-half storey house. He felt it made for an inferior design and he showed me a sketch of both options. I tended to agree with him. The low eaves version was in fact exactly the same floor area but headroom was lost on the upper floor and he reckoned he would lose a bedroom in the planner’s preferred arrangement. Also the planners’ preferred version was much more roof-dominant, which he felt just didn’t look as good. Basically he wanted a country cottage look whilst the planners were insisting on….a bungalow with a loft conversion.
Of course, nowhere in any planning guidance is there a definition of what is meant by a one-and-a-half storey house. No, that would be far too helpful. So the very vagueness of the term allows lots of room for planners to make up arbitrary rulings. The planning inspector who had granted permission for this house on appeal hadn’t seen fit to mention any specific ridge height, which would have introduced a little clarity to the situation. In fact, there was a difference in ridge heights — 8m for our man’s preferred version as against 7.1 for the planners. However, the position of the house hardly merited any height restriction and none of the neighbours had expressed any concern about the design of the house.
So just what should he do? He had yet to put in a detailed application for either version of the house. Should he go for the easy life and get permission for the version the planners had given the nod to. Or fight for the version he wanted. The planners would recommend refusal on that but that would give the final say to the committee who, he thought, might just see sense. His best bet was probably to apply for the his preferred version and be prepared to take in to appeal if it was turned down, whilst subsequently making a second application for the uncontroversial design so that he would be sure of at least being able to build something before the whole planning application went dead after three years.
But what a palaver? Why should anyone have to jump through such an extraordinary set of hoops in the first place. In ten years’ time, whatever gets built there will have become accepted as part and parcel of the neighbourhood and no one will bat an eyelid if the house is 8m high or 7.1m high, or where the eaves level is. So why the compulsion to meddle in the minutiae of house design like this? Why not just let him get on and build what he thinks of as a one-and-a-half storey house?
The online ramblings of Housebuilder's Bible author Mark Brinkley. The paper version is updated every two years and is widely available via UK bookstores and Amazon
27 Sept 2006
25 Sept 2006
Florida property scams
I spent about an hour on Saturday browsing around the International Property Show being held at London’s Excel exhibition centre. These types of show have become very common in the past few years but it was my first visit to one and it was certainly an eye-opener. There must have been 400 or 500 stands all appearing to sell much the same sort of thing — holiday apartments and houses — at a bewildering choice of worldwide locations. The places you might expect were much in evidence: Florida, Spain, Portugal, Dubai, plus a smattering of East European developments with Bulgaria very much to the fore.
But these shows aren’t just shop windows for overseas estate agents. What it’s all about is property speculation. Putting deposits down, buying off plan, and then either selling on for a quick turn or holding on for holiday lets. Most of the visitors have, I understand, already done one or two deals and they are there hunting out the best returns for new investments.
I sort of ambled about looking at various stands, trying to avoid direct eye contact with the many pretty girls employed to pull the punters into a dialogue with the sales teams. Then I got trapped by an earnest young Englishmen who wanted to tell me about his flip scheme. No, I’d never heard the term, either.
Apparently, it’s a guaranteed method of turning $20k into $29k. Sounds good. What I have to do is put a deposit down on an as-yet-unbuilt 3 bedroomed bungalow in Port Charlotte in Florida. The finished bungalows have been “appraised” at $364k and will be bought at this price when completed. If the market won’t bear it, the developer will, via something called a Guaranteed Buy Back Guarantee. That’s two guarantees for the price of one! They are currently offering the bungalows at just $335k, and you only need to put down a deposit of $20k to secure one: you don’t even need to pay any interest on the mortgage you take out because that appears to be rolled up into the price by the developer. You pocket the difference, $29k, when the deal is completed. You don’t even need to go to Florida.
“It sounds too good to be true,” I commented to him, trying to sound just a little bit sceptical.
“I guarantee you that it works,” he said, without any hint of irony.
“But I have just been reading that the Florida property market is in freefall.”
“Oh, the media loves to scare people, doesn’t it? It’s really only falling in one of two over-blown hot spots where development has run out of control. I can assure you that Florida as a whole remains the fastest growing property market in the world. And this site is really well positioned. We do an incredible amount of research before we select the right properties for our schemes.”
“Well I wouldn’t invest without at least visiting the site.”
“No need to do that,” he said. “We’ve undertaken all the necessary due diligence already.”
At this point, I think he saw me sucking my teeth and decided I was not really much of a sales catch and so the conversation sort of petered out. I went away clutching his distinctly unglossy handout.
But it set me thinking. Lots of people obviously do go for all this stuff, otherwise this show wouldn’t have been taking place. And I have no doubt that, if the market keeps rising, they may even make some money out of these schemes.
But Florida isn’t a rising market. And why do they need to guarantee a guarantee? Maybe this sort of thing is for you but it’s definitely not my cup of tea. Take a peek at their website, see if you can make sense of it…www.propertyqc.com
But these shows aren’t just shop windows for overseas estate agents. What it’s all about is property speculation. Putting deposits down, buying off plan, and then either selling on for a quick turn or holding on for holiday lets. Most of the visitors have, I understand, already done one or two deals and they are there hunting out the best returns for new investments.
I sort of ambled about looking at various stands, trying to avoid direct eye contact with the many pretty girls employed to pull the punters into a dialogue with the sales teams. Then I got trapped by an earnest young Englishmen who wanted to tell me about his flip scheme. No, I’d never heard the term, either.
Apparently, it’s a guaranteed method of turning $20k into $29k. Sounds good. What I have to do is put a deposit down on an as-yet-unbuilt 3 bedroomed bungalow in Port Charlotte in Florida. The finished bungalows have been “appraised” at $364k and will be bought at this price when completed. If the market won’t bear it, the developer will, via something called a Guaranteed Buy Back Guarantee. That’s two guarantees for the price of one! They are currently offering the bungalows at just $335k, and you only need to put down a deposit of $20k to secure one: you don’t even need to pay any interest on the mortgage you take out because that appears to be rolled up into the price by the developer. You pocket the difference, $29k, when the deal is completed. You don’t even need to go to Florida.
“It sounds too good to be true,” I commented to him, trying to sound just a little bit sceptical.
“I guarantee you that it works,” he said, without any hint of irony.
“But I have just been reading that the Florida property market is in freefall.”
“Oh, the media loves to scare people, doesn’t it? It’s really only falling in one of two over-blown hot spots where development has run out of control. I can assure you that Florida as a whole remains the fastest growing property market in the world. And this site is really well positioned. We do an incredible amount of research before we select the right properties for our schemes.”
“Well I wouldn’t invest without at least visiting the site.”
“No need to do that,” he said. “We’ve undertaken all the necessary due diligence already.”
At this point, I think he saw me sucking my teeth and decided I was not really much of a sales catch and so the conversation sort of petered out. I went away clutching his distinctly unglossy handout.
But it set me thinking. Lots of people obviously do go for all this stuff, otherwise this show wouldn’t have been taking place. And I have no doubt that, if the market keeps rising, they may even make some money out of these schemes.
But Florida isn’t a rising market. And why do they need to guarantee a guarantee? Maybe this sort of thing is for you but it’s definitely not my cup of tea. Take a peek at their website, see if you can make sense of it…www.propertyqc.com
21 Sept 2006
Who'd be a pressure tester?
I spent yesterday morning with Keith Bartlett who runs a business called Air Leakage Testing based in Saffron Walden in Essex. Keith had a pressure test booked on a renovated house in Greenwich, SE London, and I was getting to ride shot gun with him, picking his brains as we travelled down the M11 in his van with all the kit in the back.
Keith’s background is running a building business erecting steel structures as industrial units. A requirement for air pressure testing for buildings larger than 1000m2 in floor area came into effect in 2002 and Keith took a view that this was the start of a trend and decided, with two partners, to start this new venture to get in on the beginning of a new business opportunity. Together, they have invested something like £150,000, not to mention thousands of hours labour, to get things up and running and they fully expected to be rushed off their feet by now, since the requirement for air pressure testing was extended to new homes in April this year, under the changes to Part L of the building regs.
But it hasn’t worked out quite that way. At least, not yet. Building inspectors have yet to get to grips with the changes in Part L and there is still only a tiny trickle of work coming their way, despite their being less than a dozen firms offering a similar service. In theory, when the new Part L bites, air pressure tests should be carried out on every dwelling type used in a development. That’s a difficult figure to put an exact number to but it must be of the order of 10 to 20 thousand a year throughout the country, not to mention a significant increase in commercial work as well as here the size limit for testing has been reduced from 1000m2 to 500m2. If Keith’s business is typical, it appears that the actual number of air pressure tests being carried out is less than 10% of this figure.
What appears to be happening is that as many as 80% of qualifying commercial buildings are passed by building control without a pressure test. It seems building control are happy to accept “robust details” as an alternative method of compliance, despite there being officially no allowance for this in Part L. This may also prove to be the case with domestic work as well, although the reasons here for slow take-up of pressure testing are to do with the delayed adoption of the 2006 Part L regulations by local authorities.
Thus far the main take up in the domestic sector has been from architects and interested clients who are testing the water and trying to get to grips with the concept air pressure testing. Keith told me: “Architects are in fact often their own worst enemies because the buildings they design are over-complex and full of junctions, just the type of structures that perform badly in an air pressure test.”
The actual test normally takes a couple of hours but there is usually a costly transport element to be taken into account because testers are thin on the ground and one test frequently takes up a full day. So the cost is typically around £300 plus transport for a single house, though it can be much less if there are multiple houses ready to test on the same site. “Most builders feel that they have carried out a reasonable job and are deeply suspicious of pressure testing. If the readings suggest that the house is leaky, they start questioning the accuracy of the equipment. So then we do a smoke test and this shows precisely where the leaks are. Then they believe.”
I was hoping to witness and photograph the test in Greenwich. But the traffic around the Blackwall Tunnel was gridlocked and after sitting in the van for two and a half hours without even reaching our destination, Keith aborted the mission and rescheduled for another day. With more than a touch of irony, I reflected on how the intention of an air pressure test is to save energy consumption, but London’s chaotic road system had ended up with us wasting rather a lot of fuel, achieving precisely nothing. That’s the politics of energy for you.
Keith’s background is running a building business erecting steel structures as industrial units. A requirement for air pressure testing for buildings larger than 1000m2 in floor area came into effect in 2002 and Keith took a view that this was the start of a trend and decided, with two partners, to start this new venture to get in on the beginning of a new business opportunity. Together, they have invested something like £150,000, not to mention thousands of hours labour, to get things up and running and they fully expected to be rushed off their feet by now, since the requirement for air pressure testing was extended to new homes in April this year, under the changes to Part L of the building regs.
But it hasn’t worked out quite that way. At least, not yet. Building inspectors have yet to get to grips with the changes in Part L and there is still only a tiny trickle of work coming their way, despite their being less than a dozen firms offering a similar service. In theory, when the new Part L bites, air pressure tests should be carried out on every dwelling type used in a development. That’s a difficult figure to put an exact number to but it must be of the order of 10 to 20 thousand a year throughout the country, not to mention a significant increase in commercial work as well as here the size limit for testing has been reduced from 1000m2 to 500m2. If Keith’s business is typical, it appears that the actual number of air pressure tests being carried out is less than 10% of this figure.
What appears to be happening is that as many as 80% of qualifying commercial buildings are passed by building control without a pressure test. It seems building control are happy to accept “robust details” as an alternative method of compliance, despite there being officially no allowance for this in Part L. This may also prove to be the case with domestic work as well, although the reasons here for slow take-up of pressure testing are to do with the delayed adoption of the 2006 Part L regulations by local authorities.
Thus far the main take up in the domestic sector has been from architects and interested clients who are testing the water and trying to get to grips with the concept air pressure testing. Keith told me: “Architects are in fact often their own worst enemies because the buildings they design are over-complex and full of junctions, just the type of structures that perform badly in an air pressure test.”
The actual test normally takes a couple of hours but there is usually a costly transport element to be taken into account because testers are thin on the ground and one test frequently takes up a full day. So the cost is typically around £300 plus transport for a single house, though it can be much less if there are multiple houses ready to test on the same site. “Most builders feel that they have carried out a reasonable job and are deeply suspicious of pressure testing. If the readings suggest that the house is leaky, they start questioning the accuracy of the equipment. So then we do a smoke test and this shows precisely where the leaks are. Then they believe.”
I was hoping to witness and photograph the test in Greenwich. But the traffic around the Blackwall Tunnel was gridlocked and after sitting in the van for two and a half hours without even reaching our destination, Keith aborted the mission and rescheduled for another day. With more than a touch of irony, I reflected on how the intention of an air pressure test is to save energy consumption, but London’s chaotic road system had ended up with us wasting rather a lot of fuel, achieving precisely nothing. That’s the politics of energy for you.
8 Sept 2006
The Demise of Outline Planning Permission
If you want a good example of how our reforming government manages to make most things worse than they were before, you need look no further than what’s just happened to outline planning permissions.
Planning applications have traditionally fallen into two distinct categories, outline and detailed. You can’t build without detailed permission, but you can use outline to establish a right to build. Thus if you wanted to work out whether you could build a new house in your back garden, you could apply for outline permission and, if successful, that would give you three years to submit a detailed application for exactly what it was you wanted to build.
Now, traditionally, all you needed for an outline permission was a location plan at 1:1250 and a site plan at 1:500, with the site in question outlined in red. Anyone who could handle a photocopier had the skills to submit an outline application. If the site was difficult, there might have had to be some attention paid to things like parking or access but mostly it was just a red line on a map.
No more.
In future, outline permission will have to include information on the footprint to be developed, together with upper and lower limits on height, width and length of each and every new building. You will also have to submit information about the access arrangements. Now you can’t realistically do this without drawing up some sketches at the very least. Not only is this time consuming and expensive but it also restricts your options if and when outline planning is achieved.
One of the beauties of the old system was that you could start with a blank sheet of paper when it came to siting, sizing and detailing your house. OK, you would get involved in interminable discussions with the planners about what you could and couldn’t get away with, but at least you had the luxury of choice. Now you have to commit yourself to a shape, size and situation just to win outline permission. Just about all that would be left after this would be a few arguments over windows, bricks and roof tiles, the sort of details that used to be called reserved matters.
It’s hard to see who gains by these new rules.
The applicant is severely disadvantaged because they now have to undertake most of the design work on spec, without even knowing whether the scheme as a whole is even acceptable. Which, in turn, means that the resulting designs are likely to be much more timid and less challenging. And a lot of time and money will be wasted.
The other side of the coin is that the planners have much more negotiating power because they have the threat of throwing out the entire scheme now, where previously both sides knew that something could be built and that a compromise would have to emerge. But do the planners actually want or need this added elbow room? They are already snowed under with the workload from domestic applications, of which 90% get passed. This will only increase their workload because they will now have to make value judgments about whether the application in front of them merits approval based on God Knows What criteria and this in turn may well involve several applications on each site.
They might just as well have axed outline planning permissions altogether and be done with. But no, the pretence that the outline planning stage still exists is held onto, thus making a difficult task — obtaining planning permission — even more difficult, risky, time consuming and expensive. In other words, another classic New Labour reform. How do they do it?
Planning applications have traditionally fallen into two distinct categories, outline and detailed. You can’t build without detailed permission, but you can use outline to establish a right to build. Thus if you wanted to work out whether you could build a new house in your back garden, you could apply for outline permission and, if successful, that would give you three years to submit a detailed application for exactly what it was you wanted to build.
Now, traditionally, all you needed for an outline permission was a location plan at 1:1250 and a site plan at 1:500, with the site in question outlined in red. Anyone who could handle a photocopier had the skills to submit an outline application. If the site was difficult, there might have had to be some attention paid to things like parking or access but mostly it was just a red line on a map.
No more.
In future, outline permission will have to include information on the footprint to be developed, together with upper and lower limits on height, width and length of each and every new building. You will also have to submit information about the access arrangements. Now you can’t realistically do this without drawing up some sketches at the very least. Not only is this time consuming and expensive but it also restricts your options if and when outline planning is achieved.
One of the beauties of the old system was that you could start with a blank sheet of paper when it came to siting, sizing and detailing your house. OK, you would get involved in interminable discussions with the planners about what you could and couldn’t get away with, but at least you had the luxury of choice. Now you have to commit yourself to a shape, size and situation just to win outline permission. Just about all that would be left after this would be a few arguments over windows, bricks and roof tiles, the sort of details that used to be called reserved matters.
It’s hard to see who gains by these new rules.
The applicant is severely disadvantaged because they now have to undertake most of the design work on spec, without even knowing whether the scheme as a whole is even acceptable. Which, in turn, means that the resulting designs are likely to be much more timid and less challenging. And a lot of time and money will be wasted.
The other side of the coin is that the planners have much more negotiating power because they have the threat of throwing out the entire scheme now, where previously both sides knew that something could be built and that a compromise would have to emerge. But do the planners actually want or need this added elbow room? They are already snowed under with the workload from domestic applications, of which 90% get passed. This will only increase their workload because they will now have to make value judgments about whether the application in front of them merits approval based on God Knows What criteria and this in turn may well involve several applications on each site.
They might just as well have axed outline planning permissions altogether and be done with. But no, the pretence that the outline planning stage still exists is held onto, thus making a difficult task — obtaining planning permission — even more difficult, risky, time consuming and expensive. In other words, another classic New Labour reform. How do they do it?
6 Sept 2006
On ICFs
There is an ingenious way of building walls using polystyrene and concrete. You use the polystyrene as formwork to build up the walls into the shape you want, then you pour concrete into the formwork and, voila, you have a structural wall with insulation already built in.
These systems, and there are several, are known generically as Insulated Concrete Formwork (ICFs). They are not new and they haven’t really made the splash that their proponents had hoped for, but there are signs that the market for ICF systems is at last coming alive. In the UK and Ireland, there are now about a dozen active promoters whereas five years ago it was basically just one. And there are indications that the crucial developer market is at last coming on board and seeing the potential of building homes with ICFs.
What are the plus points?
• It’s a quick building method – comparable with timber frame
• It’s semi-skilled
• It’s simple: the number of elements needed to make up an external wall are greatly reduced
• It can be cheaper – if you restrict your choice of external wall cladding to pre-coloured renders
• You get fantastic insulation levels
• Other benefits include good airtightness and soundproofing
And the negatives?
• The headline price, usually around £30 per m2 for the polystyrene formwork, plus £10 per m2 for the readymix to fill it, puts a lot of people off. You can construct a blockwork wall, labour included, for around £20 per m2, so why would you want to start with a wall system that costs twice as much? I know one or two people who have got as far as this and no further. But if you compare finished wall costs, it looks very different. A fully finished brick and block wall with insulated cavity costs between £80 and £100 per m2. An ICF really shouldn’t be any more than this and if finished with an external render should be less than £80 per m2 overall.
• Pouring the concrete is critical and can be a little bit scary. Building with ICFs may be “semi-skilled,” but it’s definitely not unskilled. There is a knack, which you have to learn. The walls wobble about and you have to be confident that you have your bracing just right.
• Bursts. It’s not difficult to overstress the formwork when pouring concrete. This can cause the formwork to split open and for the readymix to spill over onto the ground. It looks worse than it actually is and it’s part of the skill to know how to handle the odd burst without panicking. But it doesn’t look good and it contributes in no small part to a negative perception of ICFs.
• Concrete. Although all the ICF promoters sell their systems as a green method of building, they can’t get away from the fact that concrete is not perceived as a green building material. Far from it. It is regularly subject to scathing attack from environmentalists and is blacklisted from many deep-green projects, along with all cement-based products. Personally, I think this is a ridiculous state of affairs, especially as these projects almost always promote the questionable use of lime as a replacement for cement. But nevertheless, these perceptions count. Concrete is just not sexy, in the way timber, glass or handmade bricks are sexy.
• Neither, for that matter, is polystyrene!
• Not so much thermal mass as thermal mish-mash. I have written recently on the blog about the perceived joys of thermal mass as a method of storing passive solar heat and evening-out temperature fluctuations. I remain somewhat sceptical of the wilder claims made by thermal mass advocates but the problem for ICF walls is that the concrete is insulated by the polystyrene casing both inside and out, so it’s not readily available to admit heat radiation. Thermal mass fans find this incredibly frustrating, so much so that I know of at least one project where the architect instructed the builders to peel off the entire inside layer of polystyrene after the concrete had set and to then stick it onto the outside. Inelegant or what?
Summary
I have written at far greater length about the negatives than I have about the positives. If word counters measured opinions, you would surmise I am therefore broadly negative. But that’s not so. It really doesn’t bother me that ICFs are made of concrete, or that the thermal mass is compromised by the insulation, or that headline price looks high, or that they are not quite as easy to build with as you might initially think. In July and August, I visited two ICF sites, one a selfbuild and the other a 25 unit development, where the respective builders were both chuffed to bits with their decision to use ICFs. The selfbuilder was particularly instructive as he was a carpenter by trade and you would have thought he would naturally have gravitated towards a timber house. But no, he wanted full control of the project and he wanted to undertake virtually every trade himself. As he put it, “I’d rather just do it myself than spend time explaining to someone else what I wanted them to do, only for them to do it wrong.” In fact, the skills of a carpenter are far more appropriate for ICF builds than the skills of a blocklayer, which they are designed to replace.
It remains to be seen just where ICFs go from here. As the regulations demand more and more insulation, it becomes increasingly challenging to work this into the standard cavity wall routine and builders become more open to novel format like ICFs and SIPs. At the moment, you can still build with a 100mm cavity and pass muster with Part L but the next version may require a 150mm cavity and that is stretching it some. At that point, we may suddenly see a really big switchover to ICFs, especially by those builders who instinctively don’t like timber based wall systems. Ireland has already seen a significant take-up of ICFs, but there it seems to be more about meeting the seemingly insatiable demand for new homes by whatever means available. In the UK, the new homes market is very different.
These systems, and there are several, are known generically as Insulated Concrete Formwork (ICFs). They are not new and they haven’t really made the splash that their proponents had hoped for, but there are signs that the market for ICF systems is at last coming alive. In the UK and Ireland, there are now about a dozen active promoters whereas five years ago it was basically just one. And there are indications that the crucial developer market is at last coming on board and seeing the potential of building homes with ICFs.
What are the plus points?
• It’s a quick building method – comparable with timber frame
• It’s semi-skilled
• It’s simple: the number of elements needed to make up an external wall are greatly reduced
• It can be cheaper – if you restrict your choice of external wall cladding to pre-coloured renders
• You get fantastic insulation levels
• Other benefits include good airtightness and soundproofing
And the negatives?
• The headline price, usually around £30 per m2 for the polystyrene formwork, plus £10 per m2 for the readymix to fill it, puts a lot of people off. You can construct a blockwork wall, labour included, for around £20 per m2, so why would you want to start with a wall system that costs twice as much? I know one or two people who have got as far as this and no further. But if you compare finished wall costs, it looks very different. A fully finished brick and block wall with insulated cavity costs between £80 and £100 per m2. An ICF really shouldn’t be any more than this and if finished with an external render should be less than £80 per m2 overall.
• Pouring the concrete is critical and can be a little bit scary. Building with ICFs may be “semi-skilled,” but it’s definitely not unskilled. There is a knack, which you have to learn. The walls wobble about and you have to be confident that you have your bracing just right.
• Bursts. It’s not difficult to overstress the formwork when pouring concrete. This can cause the formwork to split open and for the readymix to spill over onto the ground. It looks worse than it actually is and it’s part of the skill to know how to handle the odd burst without panicking. But it doesn’t look good and it contributes in no small part to a negative perception of ICFs.
• Concrete. Although all the ICF promoters sell their systems as a green method of building, they can’t get away from the fact that concrete is not perceived as a green building material. Far from it. It is regularly subject to scathing attack from environmentalists and is blacklisted from many deep-green projects, along with all cement-based products. Personally, I think this is a ridiculous state of affairs, especially as these projects almost always promote the questionable use of lime as a replacement for cement. But nevertheless, these perceptions count. Concrete is just not sexy, in the way timber, glass or handmade bricks are sexy.
• Neither, for that matter, is polystyrene!
• Not so much thermal mass as thermal mish-mash. I have written recently on the blog about the perceived joys of thermal mass as a method of storing passive solar heat and evening-out temperature fluctuations. I remain somewhat sceptical of the wilder claims made by thermal mass advocates but the problem for ICF walls is that the concrete is insulated by the polystyrene casing both inside and out, so it’s not readily available to admit heat radiation. Thermal mass fans find this incredibly frustrating, so much so that I know of at least one project where the architect instructed the builders to peel off the entire inside layer of polystyrene after the concrete had set and to then stick it onto the outside. Inelegant or what?
Summary
I have written at far greater length about the negatives than I have about the positives. If word counters measured opinions, you would surmise I am therefore broadly negative. But that’s not so. It really doesn’t bother me that ICFs are made of concrete, or that the thermal mass is compromised by the insulation, or that headline price looks high, or that they are not quite as easy to build with as you might initially think. In July and August, I visited two ICF sites, one a selfbuild and the other a 25 unit development, where the respective builders were both chuffed to bits with their decision to use ICFs. The selfbuilder was particularly instructive as he was a carpenter by trade and you would have thought he would naturally have gravitated towards a timber house. But no, he wanted full control of the project and he wanted to undertake virtually every trade himself. As he put it, “I’d rather just do it myself than spend time explaining to someone else what I wanted them to do, only for them to do it wrong.” In fact, the skills of a carpenter are far more appropriate for ICF builds than the skills of a blocklayer, which they are designed to replace.
It remains to be seen just where ICFs go from here. As the regulations demand more and more insulation, it becomes increasingly challenging to work this into the standard cavity wall routine and builders become more open to novel format like ICFs and SIPs. At the moment, you can still build with a 100mm cavity and pass muster with Part L but the next version may require a 150mm cavity and that is stretching it some. At that point, we may suddenly see a really big switchover to ICFs, especially by those builders who instinctively don’t like timber based wall systems. Ireland has already seen a significant take-up of ICFs, but there it seems to be more about meeting the seemingly insatiable demand for new homes by whatever means available. In the UK, the new homes market is very different.
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